構造依存希土類合金の開発と磁気熱量・熱弾性材料への展開

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Title

構造依存希土類合金の開発と磁気熱量・熱弾性材料への

_展開

Author(s)

雨海, 有佑; 塩尻, 泰広; 鈴木, 拓也; 石原, 圭; 村山, 茂幸

Citation

室蘭工業大学紀要 Vol.63, pp.37-40, 2014

Issue Date

2014-03-18

URL

http://hdl.handle.net/10258/2828

Rights

－　37　－ ᡁ ಟ஧㸪㜿Ἴຍ ῟஧㸪⸨ ⪔୍㑻

- 36 -

ࡣᑠࡉ࠸ࡀࠊ㉸ఏᑟ࣐ࢢࢿࢵࢺࡢ฼⏝ࢆ᝿ᐃࡋࡓ₅ T ࡛ࡣ኱ࡁ࡞|Sm|ࡀ☜ㄆࡉࢀࡿࠋ12 K ࡢ➼ ≧ែ ࡛_{5 T ࡢ☢ሙࢆ༳ຍࡋࠊ᩿⇕≧ែ࡛ᾘ☢ࡋࡓሙྜࡢ}  ᗘῶᑡࡣࠊᅗ_2(b)࠿ࡽTad= 5.8 K ࡜ぢ✚ࡶࡽࢀ ࡿࠋ☢Ẽ෭෾ᮦ࡜ࡋ࡚᥋ࡍࡿ≀㉁࠿ࡽ⇕ࢆዣ࠺ࡓ ࡵ࡟ࡣࠊ༢఩య✚࠶ࡓࡾࡢ࢚ࣥࢺࣟࣆ࣮ῶᑡࡀ኱ ࡁ࠸ᚲせࡀ࠶ࡿࡀࠊᮏ⣔ࡣ_Dy2S3࡜࠸࠺໬Ꮫᘧ࠿ࡽ ࢃ࠿ࡿࡼ࠺࡟ᕼᅵ㢮ᐦᗘࡀప࠸ศ୙฼࡛࠶ࡿࠋࡋ ࠿ࡋࠊ_α-R2S3ࡢእሙ࡟ᑐࡍࡿ≉␗࡞≀ᛶᛂ⟅ࢆ฼⏝ ࡋࠊ☢Ẽ⇕㔞ຠᯝࢆไᚚࡋᚓࢀࡤࠊእሙไᚚ࡜࠸ ࠺௜ຍ౯್ࢆࡶࡗࡓ☢Ẽ෭෾ᮦࡀᐇ⌧ࡋᚓࡿࡢ࡛ ࡣ࡞࠸࠿࡜࠸࠺ほⅬ࡛ᇶ♏≀ᛶ◊✲ࢆ㐍ࡵ࡚࠸ࡿࠋ 5 ࡲ࡜ࡵ  ᕼᅵ㢮◲໬≀ α-R2S3༢⤖ᬗࡢ↓☢ሙୗ࠾ࡼࡧ☢ ሙ୰ẚ⇕ࢆ ᐃࡋࠊ_α-Gd2S3ࡢ⵳෭ᮦ࡜ࡋ࡚ࡢྍ⬟ ᛶࠊα-Dy2S3ࡢ☢Ẽ෭෾ᮦ࡜ࡋ࡚ࡢྍ⬟ᛶࢆぢฟࡋ ࡓࠋࡋ࠿ࡋᐇᮦᩱ࡜ࡋ࡚ࡢඃ఩ᛶ࡟ࡘ࠸࡚ࡣࠊከ ࡃࡢ᳨ウࡍ࡭ࡁㄢ㢟ࡀṧࡉࢀ࡚࠸ࡿࠋα-R2S3ࡢ☢Ẽ ⇕㔞ຠᯝࢆእሙไᚚࡍࡿྍ⬟ᛶ࡟ࡘ࠸࡚ࡶࠊ௒ᚋ ࡉࡽ࡟᳨ウࡋ࡚࠸ࡃࠋ ㅰ㎡  ᮏ◊✲ࡢ୍㒊ࡣ_{JSPS ⛉◊㈝ 23540384 ࡢຓᡂࢆ} ཷࡅ࡚࡞ࡉࢀࡲࡋࡓࠋ ཧ⪃ᩥ⊩

(1) V. K. Pecharsky and K. A. Gschneidner, Jr., Giant Magnetocaloric Effect in Gd5(Si2Ge2), Phys. Rev. Lett.,

76 (1997) p4494-4497.

(2) V. K. Pecharsky and K. A. Gschneidner, Jr., Tunable magnetic regenerator alloys with a giant magnetocaloric effect for magnetic refrigeration from ~20 to ~290̴K, Appl. Phys. Lett., 70 (1997) p3299-3301.

(3) A. Fujita, S. Fujieda, Y. Hasegawa, and K. Fukamichi, Itinerant-electron metamagnetic transition and large magnetocaloric effects in La(FexSi1-x)13 compounds and their hydrides, Phys. Rev. B, 67 (2003) 104416(12 pages).

(4) A. Fujita, S. Fujieda, K. Fukamichi, Y. Yamazaki, and Y. Iijima, Giant Magnetic Entropy Change in Hydrogenated La(Fe0.88Si0.12)13Hy Compounds, Mater. Trans., 43 (2002)

p653-655.

(5) H. Wada, and Y. Tanabe, Giant magnetocaloric effect of MnAs1−xSbx, Appl. Phys. Lett., 79 (2001) p3302- 3304.

(6) O. Tegus, E. Brück, K. H. J. Buschow, and F. R. de Boer, Transition-metal-based magnetic refrigerants for room- temperature applications, Nature, 415 (2002) p150- 152.

(7) S. Kikegawa, T. Matsumura, S. Murayama, H. Takano, and Y. Obi, Magnetic properties of amorphous Mn100_xCex alloys, Physica B, 329–333 (2003)

p1074–1076.

(8) S. Kikegawa, Y. Amakai, K. Asano, S. Murayama, H. Takano, and Y. Obi, Specific heat of amorphous Mn100-xCex alloys, J. Magn. Mag. Mater., 272-276 (2004)

p72-74.

(9) Y. Amakai, S. Murayama, Y. Obi, H. Takano, N. Momono, and K. Takanashi, Thermal expansion of structure-disordered heavy-fermion Ce alloys, J. Phys. Soc. Jpn., 80 (2011) SA057 (3 pages).

(10) N. Momono, S. Kuribayashi, Y. Amakai, S. Murayama, S Torii, and H. Takano, Stripe order and supercon- ductivity in the mechanically milled La1.6-xNd0.4SrxCuO4, J. Phys.: Conf. Ser., 400 (2012) 022077 (4 pages). (11) S. Ebisu, Y. Iijima, T. Iwasa, and S. Nagata,

Antiferromag- netic transition and electrical conductivity in -Gd2S3, J. Phys. Chem. Solids, 65 (2004) p1113-1120.

(12) S. Ebisu, M. Gorai, K. Maekawa, and S. Nagata, Highly Anisotropic Properties of Antiferromagnetic -Tb2S3 Single Crystal, AIP Conf. Proc., 850 (2006), p1237-1238.

(13) S. Ebisu, M. Narumi, and S. Nagata, Anomalous enlarge- ment of electrical resistivity between successive mag- netic transitions in -Dy2S3, J. Phys. Soc. Jpn., 75 (2006) 085002 (2 pages).

(14) S. Ebisu, M. Narumi, M. Gorai, S. Nagata, Successive magnetic phase transitions in -Dy2S3 single crystal, J. Magn. Magn. Mater., 310 (2007) p1741-1743.

(15) S. Ebisu, K. Koyama, H. Omote, and S. Nagata, High field magnetization processes in single crystals of -Tb2S3 and -Dy2S3., J. Phys.: Conf. Ser., 150 (2009) 042027(4 pages).

(16) S. Ebisu, H. Omote, and S. Nagata, Drastic change of the electrical resistivity related to the novel magnetic phase transition in -Sm2S3, J. Phys.: Conf. Ser., 200 (2010) 092005(4 pages).

(17) S. Ebisu, K. Koyama, T. Horikoshi, M. Kokita and S. Nagata, Extremely broad hysteresis in the magnetization process of -Dy2S3 single crystal induced by high field cooling, J. Phys.: Conf. Ser., 400 (2012), 032010 (4 pages).

(18) S. Ebisu, Y. Ushiki, and S. Takahashi, Specific-heat Study on Successive Magnetic Transitions in -Dy2S3 Single Crystals under Magnetic Fields, J. Kor. Phys. Soc., 63 (2013) p571-574.

(19) M. Matsuda, K. Kakurai, S. Ebisu, and S. Nagata, Succes- sive Magnetic Phase Transitions in -Tb2S3 Studied by Neutron Diffraction Technique, J. Phys. Soc. Jpn., 75 (2006) 074710 (4 pages).

(20) M. Matsuda, A. Kikkawa, K. Katsumata, S. Ebisu, and S. Nagata, Neutron Diffraction Study of -Gd2S3, J. Phys. Soc. Jpn., 74 (2005) p1412-1415.

(21) A. Kikkawa, K. Katsumata, S. Ebisu, and S. Nagata, Phase transition of a frustrated -Gd2S3, J. Phys. Soc. Jpn., 73 (2004) p2955-2958. ᡁ ಟ஧㸪㜿Ἴຍ ῟஧㸪⸨ ⪔୍㑻

- 36 -

ࡣᑠࡉ࠸ࡀࠊ㉸ఏᑟ࣐ࢢࢿࢵࢺࡢ฼⏝ࢆ᝿ᐃࡋࡓ5 T ࡛ࡣ኱ࡁ࡞|Sm|ࡀ☜ㄆࡉࢀࡿࠋ12 K ࡢ➼ ≧ែ ࡛5 T ࡢ☢ሙࢆ༳ຍࡋࠊ᩿⇕≧ែ࡛ᾘ☢ࡋࡓሙྜࡢ  ᗘῶᑡࡣࠊᅗ_{2(b)࠿ࡽTad= 5.8 K ࡜ぢ✚ࡶࡽࢀ} ࡿࠋ☢Ẽ෭෾ᮦ࡜ࡋ࡚᥋ࡍࡿ≀㉁࠿ࡽ⇕ࢆዣ࠺ࡓ ࡵ࡟ࡣࠊ༢఩య✚࠶ࡓࡾࡢ࢚ࣥࢺࣟࣆ࣮ῶᑡࡀ኱ ࡁ࠸ᚲせࡀ࠶ࡿࡀࠊᮏ⣔ࡣDy2S3࡜࠸࠺໬Ꮫᘧ࠿ࡽ ࢃ࠿ࡿࡼ࠺࡟ᕼᅵ㢮ᐦᗘࡀప࠸ศ୙฼࡛࠶ࡿࠋࡋ ࠿ࡋࠊα-R2S3ࡢእሙ࡟ᑐࡍࡿ≉␗࡞≀ᛶᛂ⟅ࢆ฼⏝ ࡋࠊ☢Ẽ⇕㔞ຠᯝࢆไᚚࡋᚓࢀࡤࠊእሙไᚚ࡜࠸ ࠺௜ຍ౯್ࢆࡶࡗࡓ☢Ẽ෭෾ᮦࡀᐇ⌧ࡋᚓࡿࡢ࡛ ࡣ࡞࠸࠿࡜࠸࠺ほⅬ࡛ᇶ♏≀ᛶ◊✲ࢆ㐍ࡵ࡚࠸ࡿࠋ 5 ࡲ࡜ࡵ  ᕼᅵ㢮◲໬≀ α-R2S3༢⤖ᬗࡢ↓☢ሙୗ࠾ࡼࡧ☢ ሙ୰ẚ⇕ࢆ ᐃࡋࠊ_α-Gd2S3ࡢ⵳෭ᮦ࡜ࡋ࡚ࡢྍ⬟ ᛶࠊα-Dy2S3ࡢ☢Ẽ෭෾ᮦ࡜ࡋ࡚ࡢྍ⬟ᛶࢆぢฟࡋ ࡓࠋࡋ࠿ࡋᐇᮦᩱ࡜ࡋ࡚ࡢඃ఩ᛶ࡟ࡘ࠸࡚ࡣࠊከ ࡃࡢ᳨ウࡍ࡭ࡁㄢ㢟ࡀṧࡉࢀ࡚࠸ࡿࠋα-R2S3ࡢ☢Ẽ ⇕㔞ຠᯝࢆእሙไᚚࡍࡿྍ⬟ᛶ࡟ࡘ࠸࡚ࡶࠊ௒ᚋ ࡉࡽ࡟᳨ウࡋ࡚࠸ࡃࠋ ㅰ㎡  ᮏ◊✲ࡢ୍㒊ࡣJSPS ⛉◊㈝ 23540384 ࡢຓᡂࢆ ཷࡅ࡚࡞ࡉࢀࡲࡋࡓࠋ ཧ⪃ᩥ⊩

(1) V. K. Pecharsky and K. A. Gschneidner, Jr., Giant Magnetocaloric Effect in Gd5(Si2Ge2), Phys. Rev. Lett.,

76 (1997) p4494-4497.

(2) V. K. Pecharsky and K. A. Gschneidner, Jr., Tunable magnetic regenerator alloys with a giant magnetocaloric effect for magnetic refrigeration from ~20 to ~290̴K, Appl. Phys. Lett., 70 (1997) p3299-3301.

(3) A. Fujita, S. Fujieda, Y. Hasegawa, and K. Fukamichi, Itinerant-electron metamagnetic transition and large magnetocaloric effects in La(FexSi1-x)13 compounds and their hydrides, Phys. Rev. B, 67 (2003) 104416(12 pages).

(4) A. Fujita, S. Fujieda, K. Fukamichi, Y. Yamazaki, and Y. Iijima, Giant Magnetic Entropy Change in Hydrogenated La(Fe0.88Si0.12)13Hy Compounds, Mater. Trans., 43 (2002)

p653-655.

(5) H. Wada, and Y. Tanabe, Giant magnetocaloric effect of MnAs1−xSbx, Appl. Phys. Lett., 79 (2001) p3302- 3304.

(6) O. Tegus, E. Brück, K. H. J. Buschow, and F. R. de Boer, Transition-metal-based magnetic refrigerants for room- temperature applications, Nature, 415 (2002) p150- 152.

(7) S. Kikegawa, T. Matsumura, S. Murayama, H. Takano, and Y. Obi, Magnetic properties of amorphous Mn100_xCex alloys, Physica B, 329–333 (2003)

p1074–1076.

(8) S. Kikegawa, Y. Amakai, K. Asano, S. Murayama, H. Takano, and Y. Obi, Specific heat of amorphous Mn100-xCex alloys, J. Magn. Mag. Mater., 272-276 (2004)

p72-74.

(9) Y. Amakai, S. Murayama, Y. Obi, H. Takano, N. Momono, and K. Takanashi, Thermal expansion of structure-disordered heavy-fermion Ce alloys, J. Phys. Soc. Jpn., 80 (2011) SA057 (3 pages).

(10) N. Momono, S. Kuribayashi, Y. Amakai, S. Murayama, S Torii, and H. Takano, Stripe order and supercon- ductivity in the mechanically milled La1.6-xNd0.4SrxCuO4, J. Phys.: Conf. Ser., 400 (2012) 022077 (4 pages). (11) S. Ebisu, Y. Iijima, T. Iwasa, and S. Nagata,

Antiferromag- netic transition and electrical conductivity in -Gd2S3, J. Phys. Chem. Solids, 65 (2004) p1113-1120.

(12) S. Ebisu, M. Gorai, K. Maekawa, and S. Nagata, Highly Anisotropic Properties of Antiferromagnetic -Tb2S3 Single Crystal, AIP Conf. Proc., 850 (2006), p1237-1238.

(13) S. Ebisu, M. Narumi, and S. Nagata, Anomalous enlarge- ment of electrical resistivity between successive mag- netic transitions in -Dy2S3, J. Phys. Soc. Jpn., 75 (2006) 085002 (2 pages).

(14) S. Ebisu, M. Narumi, M. Gorai, S. Nagata, Successive magnetic phase transitions in -Dy2S3 single crystal, J. Magn. Magn. Mater., 310 (2007) p1741-1743.

(15) S. Ebisu, K. Koyama, H. Omote, and S. Nagata, High field magnetization processes in single crystals of -Tb2S3 and -Dy2S3., J. Phys.: Conf. Ser., 150 (2009) 042027(4 pages).

(16) S. Ebisu, H. Omote, and S. Nagata, Drastic change of the electrical resistivity related to the novel magnetic phase transition in -Sm2S3, J. Phys.: Conf. Ser., 200 (2010) 092005(4 pages).

(17) S. Ebisu, K. Koyama, T. Horikoshi, M. Kokita and S. Nagata, Extremely broad hysteresis in the magnetization process of -Dy2S3 single crystal induced by high field cooling, J. Phys.: Conf. Ser., 400 (2012), 032010 (4 pages).

(18) S. Ebisu, Y. Ushiki, and S. Takahashi, Specific-heat Study on Successive Magnetic Transitions in -Dy2S3 Single Crystals under Magnetic Fields, J. Kor. Phys. Soc., 63 (2013) p571-574.

(19) M. Matsuda, K. Kakurai, S. Ebisu, and S. Nagata, Succes- sive Magnetic Phase Transitions in -Tb2S3 Studied by Neutron Diffraction Technique, J. Phys. Soc. Jpn., 75 (2006) 074710 (4 pages).

(20) M. Matsuda, A. Kikkawa, K. Katsumata, S. Ebisu, and S. Nagata, Neutron Diffraction Study of -Gd2S3, J. Phys. Soc. Jpn., 74 (2005) p1412-1415.

(21) A. Kikkawa, K. Katsumata, S. Ebisu, and S. Nagata, Phase transition of a frustrated -Gd2S3, J. Phys. Soc. Jpn., 73 (2004) p2955-2958. 室工大紀要第_{63 号（2013） 37~40}

_{特　　　集}

ᐊᕤ኱⣖せ➨63 ྕ㸦2013㸧 37㹼40

- 37 -

ᵓ㐀౫Ꮡᕼᅵ㢮ྜ㔠ࡢ㛤Ⓨ࡜☢Ẽ⇕㔞࣭⇕ᙎᛶᮦᩱ࡬ࡢᒎ㛤

㞵ᾏ

᭷భ

*1, *2

_㸪ሷᑼ

_Ὀᗈ

*3

_㸪㕥ᮌ

_ᣅஓ

*3

_㸪▼ཎ

_ᆂ

*3

_㸪ᮧᒣ

_ⱱᖾ

*1, *2

Development of Magnetocaloric and Thermoelastic Materials in

Structure-dependent Rare-earth Alloys

Yusuke AMAKAI

*1, *2

_{, Yasuhiro SHIOJIRI}

*3

_{, Takuya SUZUKI}

*3

Kei ISHIHARA

*3

_{, and Shigeyuki MURAYAMA}

*1, *2

㸦ཎ✏ཷ௜᪥ ᖹᡂ

_{25 ᖺ 9 ᭶ 30 ᪥ ㄽᩥཷ⌮᪥ ᖹᡂ 26 ᖺ 1 ᭶ 24 ᪥㸧}

Abstract

This study aims to develop next-generation high-performance materials with utilizing the strongly correlated electronic properties in amorphous Ce-alloys. We have focused amorphous Ce-Mn alloys consisting of the rare-earth metal cerium and the transition metal manganese. We have measured the magnetostriction for amorphous Ce-Mn alloys where a large thermal expansion and anomalous temperature dependence observed. The thermal expansion of the low temperature for amorphous Ce-Mn alloys has been found to be controlled by a magnetic field. In the future, we aim at development of the drive actuator element under the control of the temperature and magnetic field. Keywords : Strongly correlated electron, Amorphous alloys, Thermal expansion, Magnetostriction

1 ࡣࡌࡵ࡟ ᕼᅵ㢮ඖ⣲ࢆྵࡴ㔠ᒓ㛫໬ྜ≀ࡸྜ㔠ࡣ㸪ᕼᅵ 㢮ࡢ㟁Ꮚࡀ≉ᐃࡢ㌶㐨㸦_{4f ㌶㐨㸧࡟᮰⦡ࡉࢀࡿࡓ} ࡵᒁᅾᛶࡀᙉࡃ㸪㟁Ꮚྠኈࡢࢡ࣮ࣟࣥ┦஫స⏝ࡀ ↓ど࡛ࡁ࡞࠸ࡓࡵ㸪ᙉ࠸㟁Ꮚ┦㛵㸦ᙉ┦㛵㟁Ꮚ≧ ែ㸧ࢆᐇ⌧ࡍࡿ㸬ࡇࡢᙉ┦㛵㟁Ꮚ≧ែࡣ㸪ᕧ኱⇕ ᐜ㔞࣭ወጁ࡞☢Ẽ┦㌿⛣࣭ᕧ኱☢Ẽ᢬ᢠ࣭␗ᖖ⇕ ⭾ᙇ࣭⇕㟁ኚ᥮≉ᛶ࣭㠀ᚑ᮶ᆺ㉸ఏᑟ࡞࡝ከᙬ࡛ 㨩ຊⓗ࡞≀ᛶࢆ♧ࡍࡇ࡜ࡀ▱ࡽࢀ࡚࠸ࡿࠋࡇࢀࡽ ࡢ≉ᛶࡣ㸪⤖ᬗᵓ㐀ࡸእሙ㸦☢ሙ࣭ ᗘ࣭ᅽຊ࣭ 㟁ሙ➼㸧࡟ࡼࡗ࡚኱ࡁࡃ≉ᛶࢆኚ໬ࡉࡏࡿ㸬ᚑࡗ ࡚ᕼᅵ㢮ࢆྵࡴ㔠ᒓ㛫໬ྜ≀ࡸྜ㔠ࡣ㸪ࡕࡻࡗ࡜ ࡋࡓࢳ࣮ࣗࢽࣥࢢ࡟ࡼࡗ࡚᭷ᮃ࡞ḟୡ௦ࡢ㧗ᶵ⬟ ᮦᩱ࡜ࡋ࡚᭷ຊ࡞ྍ⬟ᛶࢆ⛎ࡵ࡚࠸ࡿ㸬 *1 ᐊ⹒ᕤᴗ኱Ꮫ ࡋࡃࡳ᝟ሗ⣔㡿ᇦ *2 ᐊ⹒ᕤᴗ኱Ꮫ ⎔ቃㄪ࿴ᮦᩱᕤᏛ◊✲ࢭࣥࢱ࣮ *3 ᐊ⹒ᕤᴗ኱Ꮫ ᛂ⏝⌮໬Ꮫ⣔ᑓᨷ  ᡃࠎࡣ㸪୺࡟ᕼᅵ㢮ඖ⣲ࡢࢭ࣒ࣜ࢘㸦_Ce㸧ࢆྵ ࡴ㸪༢⤖ᬗ࠿ࡽᵓ㐀୙つ๎㸦࢔ࣔࣝࣇ࢓ࢫ㸧࡞࡝ ࡢᵝࠎ࡞ᵓ㐀ࢆᣢࡘᕼᅵ㢮໬ྜ≀࠾ࡼࡧྜ㔠ࡢ㛤 Ⓨ࡜㟁Ꮚ≀ᛶ࡟ࡘ࠸࡚◊✲ࢆ⾜ࡗ࡚ࡁࡓ㸬ࡇࢀࡲ ࡛ࡢᡂᯝ࠿ࡽ㸪ᙉ┦㛵㟁Ꮚࡀ㛵୚ࡋࡓᵝࠎ࡞㟁Ẽ ఏᑟᛶࡸ⇕≉ᛶࢆぢฟࡋ࡚ࡁࡓࡀ㸪≉࡟㸪࢔ࣔࣝ ࣇ࢓ࢫ_{(a-)Ce ྜ㔠࡟㛵ࡋ࡚㸪୙つ๎࡞ᵓ㐀࡟࠾࠸࡚} ࡶᙉ┦㛵㟁Ꮚ≧ែࡀᐇ⌧ࡍࡿࡇ࡜ࢆึࡵ࡚ぢฟࡋ ࡓ㸬ࡑࡇ࡛㸪≉࡟࢔ࣔࣝࣇ࢓ࢫྜ㔠ࢆ◊✲ᑐ㇟࡜ ࡋ࡚㸪≀㉁㛤Ⓨࢆ⾜࠸᪂ࡓ࡞ᶵ⬟ᛶᮦᩱ࡜ࡋ࡚ࡢ ྍ⬟ᛶࢆ᥈ࡗࡓ㸬࢔ࣔࣝࣇ࢓ࢫྜ㔠ࡢ◊✲ࡢ฼Ⅼ ࡣ㸪ձ⤖ᬗ໬ྜ≀࡜ࡋ࡚Ꮡᅾࡋ࡞࠸ඖ⣲ᵓᡂࡢྜ 㔠స〇ࡀྍ⬟㸪ղ௵ពࡢ⤌ᡂẚ࡛ไᚚࡋࡓヨᩱస 〇ࡀྍ⬟㸪ճ☢Ẽ␗᪉ᛶࡀ࡞࠸࡞࡝ࡢ≉㛗ࢆᣢࡘ ࡓࡵ㸪≀㉁㛤Ⓨࡢ⮬⏤ᗘࡀ㠀ᖖ࡟㧗࠸㸬ࡉࡽ࡟㸪 ࣐ࢡࣟ࡟ᆒ㉁࡞≉ᛶࡀᚓࡽࢀࡿࡇ࡜࠿ࡽ㸪ᮦᩱ≀ ᛶࡢほⅬ࠿ࡽࡶ᭷฼࡛࠶ࡿ࡜ゝ࠼ࡿ㸬ࡑࡇ࡛ᮏࢱ ࢫࢡࣇ࢛࣮ࢫ◊✲࡛ࡣ㸪ᕼᅵ㢮ඖ⣲ࡢ_{Ce ࢆ୰ᚰ࡜} ࡋࡓ࢔ࣔࣝࣇ࢓ࢫ࡞࡝ࡢᵝࠎ࡞ᵓ㐀ࢆᣢࡘ㔠ᒓ㛫

－　38　－ 㞵ᾏ ᭷భ㸪ሷᑼ Ὀᗈ㸪㕥ᮌ ᣅஓ㸪▼ཎ ᆂ㸪ᮧᒣ ⱱᖾ

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໬ྜ≀ࡸྜ㔠ࢆస〇ࡋ㸪ᇶ♏≀ᛶࡢホ౯࠿ࡽḟୡ ௦ࡢ㧗ᶵ⬟ᕼᅵ㢮㔠ᒓᮦᩱ࡜ࡋ࡚≉࡟㸪ᴟప ࠿ ࡽᐊ ⛬ᗘࡲ࡛౑⏝ ᗘᇦࢆព㆑ࡋࡓᮦᩱ࡬ࡢᒎ 㛤ࢆ┠ᣦࡍࡇ࡜ࢆ┠ⓗ࡜ࡋࡓ㸬  ࡇࢀࡲ࡛࡟_{Ce ࡜ᵝࠎ࡞ඖ⣲ࢆ⤌ࡳྜࢃࡏࡓ࢔ࣔ} ࣝࣇ࢓ࢫ_{Ce ྜ㔠ࡀ࠸ࡃࡘ࠿స〇ࡉࢀ࡚࠸ࡿࡀ㸪ࡑ} ࡢ୰࡛ࡶᡃࠎࡀୡ⏺࡛ึࡵ࡚స〇ࡋࡓ_a-CexMn100-x ྜ㔠ࡣ㸪_{Ce ࡜ Mn ࡢ 2 ඖ㔠ᒓ㛫໬ྜ≀ࡀᏑᅾࡋ࡞} ࠸ࡓࡵ㸪࢔ࣔࣝࣇ࢓ࢫᵓ㐀ࡺ࠼࡟Ꮡᅾྍ⬟࡞ྜ㔠 ࡛࠶ࡿ㸬ࡇࡢa-Ce-Mn ྜ㔠ࡢᇶ♏≀ᛶ ᐃࢆ⾜ࡗ ࡓ㸬ࡑࡢ⤖ᯝ㸪_{a-Ce-Mn ྜ㔠ࡢ Ce ప⃰ᗘഃ࡛ࡣ㸪} ప ࡛ _{Mn ࣮࣓ࣔࣥࢺࡢ෾⤖࡟ࡼࡿࢫࣆࣥࢢࣛࢫ} ┦ࡀฟ⌧ࡋࡓ㸬_{Ce ⃰ᗘ x ࡀቑຍࡍࡿ࡜㸪ࢫࣆࣥࢢ} ࣛࢫ㌿⛣ ᗘࡀῶᑡࡋx = 60 ௜㏆࡛ᾘኻࡍࡿࠋCe 㧗⃰ᗘഃ࡛ࡣ㸪_{Ce ࡢ 4f 㟁Ꮚ࡜ఏᑟ㟁Ꮚࡢΰᡂ㸦㏆} ⸨ຠᯝ㸧ࢆ㏻ࡋ㸪ᕧ኱࡞⇕ᐜ㔞ࢆᣢࡘ㔜࠸㟁Ꮚ≧ ែࡀᐇ⌧ࡍࡿ㸬ࡇࡢࡼ࠺࡟㸪⤌ᡂࡢኚ໬࡟కࡗ࡚ ≉ᛶࡀ㐃⥆ⓗ࡟ኚ໬ࡍࡿࡇ࡜ࡀࢃ࠿ࡗࡓ㸬(1-4)_ࡇࡢ ྜ㔠࡟࠾࠸࡚≉࡟⯆࿡῝࠸ᛶ㉁ࡣ㸪⇕⭾ᙇ࡛࠶ࡿ㸬 a-Ce-Mn ྜ㔠ࡢ⇕⭾ᙇࡣ㸪ᖜᗈ࠸⤌ᡂ⠊ᅖ࣭ ᗘ ⠊ᅖ࡛㏻ᖖ㔠ᒓࡼࡾᕧ኱࡛࠶ࡾ㸪≉࡟⤌ᡂࡀᣕᢠ ࡍࡿx = 50 ࡛ࡣ㸪ᐊ ௜㏆࡛㖡ࡢಸ௨ୖࡢ⇕⭾ᙇ ಀᩘࡀほ ࡉࢀࡿ࡜࡜ࡶ࡟㸪ప ࡛⇕⭾ᙇಀᩘࡀ ቑ኱ࡍࡿወጁ࡞ ᗘ౫Ꮡᛶࡀほ ࡉࢀࡓ㸬ࡑࡇ࡛㸪 ᮏࢱࢫࢡࡢ◊✲ㄢ㢟࡜ࡋ࡚ࡲࡎ㸪_{a-Ce-Mn ྜ㔠ࡢ} ␗ᖖ࡞⇕⭾ᙇࢆゎ᫂ࡋ㸪࢔ࢡࢳ࢚࣮ࣗࢱ࣮⣲Ꮚ࡞ ࡝ࡢ⇕⭾ᙇࢆά࠿ࡋࡓᮦᩱ㛤Ⓨ࡟ᒎ㛤ࡍࡿࡇ࡜ࢆ ┠ᣦࡋࡓ㸬௒ᅇࡣ㸪⇕⭾ᙇ࡜⇕ຊᏛⓗ࡟㛵㐃ࡍࡿ ẚ⇕࡜㸪⇕⭾ᙇ࡟ᑐࡍࡿ☢ሙࡢຠᯝࢆ⤂௓ࡍࡿ㸬 2 ᐇ㦂 2㸬1 ヨᩱస〇 ヨᩱࡣ㸪_{DC 㧗㏿ࢫࣃࢵࢱἲࢆ⏝࠸࡚స〇ࡋࡓ㸬} ࢫࣃࢵࢱἲ࡜ࡣ㸪༙ᑟయⷧ⭷ࡸ㔠ᒓⷧ⭷ࡢస〇ἲ ࡢࡦ࡜ࡘ࡜ࡋ࡚Ⰻࡃ▱ࡽࢀࡓ᪉ἲ࡛࠶ࡿ㸬ᮏ◊✲ ࡛⏝࠸࡚࠸ࡿ_{DC 㧗㏿ࢫࣃࢵࢱἲࡣ㸪ẚ㍑ⓗ኱㠃✚} ࠿ࡘཌ࠸⭷_{(mm ࣮࢜ࢲ࣮)ࡢ㔠ᒓヨᩱస〇ࡀྍ⬟࡞} ࡓࡵ㸪୍ᗘࡢヨᩱస〇࡛ᵝࠎ࡞≀ᛶ ᐃࢆ⾜࠺ࡇ ࡜ࡀฟ᮶ࡿ㸬_{DC 㧗㏿ࢫࣃࢵࢱἲ࡟ࡼࡿ࢔ࣔࣝࣇ࢓} ࢫྜ㔠ࡢస〇ࣉࣟࢭࢫࡣ㸪ࡲࡎ㸪పᅽࡢ_{Ar ࢞ࢫ㞺} ᅖẼ୰ࡢࢳࣕࣥࣂ࣮ෆ࡟㸪ᑐྥࡋ࡚㓄⨨ࡉࢀࡓࣇ ࢕࣓ࣛࣥࢺ㟁ᴟ࡜࢔ࣀ࣮ࢻ㟁ᴟ㛫࡟㟁ᅽࢆ࠿ࡅ㸪 ࢢ࣮ࣟᨺ㟁࡟ࡼࡗ࡚ _{Ar ࢞ࢫࢆ㝧࢖࢜ࣥ໬ࡉࡏࡿ㸬} ࡑࡢᚋ㸪ࢱ࣮ࢤࢵࢺ㟁ᴟ࡟㈇ࡢ㧗㟁ᅽࢆ࠿ࡅࡿࡇ ࡜࡛㸪ࢱ࣮ࢤࢵࢺ㟁ᴟୖ࡟㓄⨨ࡉࢀࡓࢱ࣮ࢤࢵࢺ ྜ㔠࡟_Ar+_{࢖࢜ࣥࡀ⾪✺ࡋ㸪ࢱ࣮ࢤࢵࢺྜ㔠⾲㠃ࡢ} ཎᏊࡀࡣࡌࡁฟࡉࢀࡿ㸬ࡣࡌࡁฟࡉࢀࡓཎᏊࡣ㸪 ࢱ࣮ࢤࢵࢺྜ㔠┤ୖ࡟࠶ࡿỈ෭ࡉࢀࡓ㖡ᇶᯈ࡟⤖ ᬗ໬ࡏࡎሁ✚ࡍࡿࡓࡵ㸪⤖ᬗᵓ㐀ࢆᣢࡓ࡞࠸࢔ࣔ ࣝࣇ࢓ࢫྜ㔠ࡀᚓࡽࢀࡿ㸦ᅗ_1㸧㸬 ࡲࡓ㸪ᮏ◊✲࡛ࡣ㸪ࢫࣃࢵࢱ࡟౑⏝ࡍࡿࢱ࣮ࢤ ࢵࢺྜ㔠ࢆࣔࣀ࢔࣮ࢡ⁐ゎ࡟ࡼࡗ࡚స〇ࡋ࡚࠸ࡿ㸬 ࢱ࣮ࢤࢵࢺྜ㔠ࢆ௵ពࡢ⤌ᡂẚ࡛స〇ࡍࡿࡇ࡜࡛ ࠾࠾ࡼࡑᚲせ࡜ࡍࡿ⤌ᡂẚࡢ࢔ࣔࣝࣇ࢓ࢫྜ㔠ࢆ స〇ࡍࡿࡇ࡜ࡀ࡛ࡁࡿࠋᚓࡽࢀࡓ࢔ࣔࣝࣇ࢓ࢫྜ 㔠ࡣ㸪ᶵᲔⓗ◊☻࡛㖡ᇶᯈࢆ㝖ཤࡋ㸪ྛ✀≀ᛶ  ᐃ⏝࡟ࢲ࢖࢔ࣔࣥࢻ࢝ࢵࢱ࣮࡛ᡂᙧࡋࡓ㸬 2㸬2 ヨᩱホ౯࠾ࡼࡧ≀ᛶ ᐃ ヨᩱࡢᵓ㐀ࡣ㸪_{X ⥺ᅇᢡ ᐃ࡟ࡼࡗ࡚☜ㄆࡋࡓ㸬} ⤌ᡂࡣ㸪_{ICP Ⓨගศගศᯒἲ࠾ࡼࡧ SEM-EDS ࡞࡝} ࢆ⏝࠸࡚☜ㄆࡋࡓ㸬  ≀ᛶ ᐃࡣ㸪☢໬⋡㸪㟁Ẽ᢬ᢠ㸪ẚ⇕㸪⇕⭾ᙇ ࠾ࡼࡧ⇕㟁⬟ࡢ ᗘ౫Ꮡᛶࢆ୰ᚰ࡟⾜࠸㸪ࡑࡢ☢ Ẽⓗᛶ㉁㸪ఏᑟ≉ᛶ㸪⇕≉ᛶ࡞࡝࠿ࡽ㟁Ꮚ≧ែ࡟ ࡘ࠸࡚⪃ᐹࡋࡓ㸬 ⇕⭾ᙇࡢ ᐃ᪉ἲࡣ㸪ࢫࢺࣞ࢖ࣥࢤ࣮ࢪἲࢆ⏝ ࠸ࡓ㸬ࢫࢺࣞ࢖ࣥࢤ࣮ࢪἲ࡜ࡣ㸪㔠ᒓ⟩࡛ฟ᮶ࡓ ṍࡳࢤ࣮ࢪࡢ㟁Ẽ᢬ᢠࡢኚ໬ࡀṍࡳࡢ㔞࡟ẚ౛ࡍ ࡿࡇ࡜ࢆ฼⏝ࡋࡓṍࡳࡢ ᐃἲ࡛࠶ࡿ㸬௨๓ࡲ࡛ ࡣ㸪ᴟప ෭෾⿦⨨ࢆ⏝࠸࡚㸪_{10 K ࠿ࡽᐊ ⛬ᗘ} ࡢ ᗘ⠊ᅖ࡛↓☢ሙࡢ ᐃࢆ⾜ࡗ࡚࠸ࡓࠋࡋ࠿ࡋ㸪 ࡇࡢ᪉ἲࡢḞⅬ࡜ࡋ࡚㸪ప ᇦࡢ ᗘ୙Ᏻᐃᛶ࠿ ࡽ௚ࡢ≀ᛶ ᐃ࡟ᑐࡋ㧗࠸ ᗘ࡛ࡢ ᐃ࡟࡞ࡗ࡚ ࠸ࡓࡇ࡜࡜↓☢ሙ࡛ࡢ ᐃࡋ࠿ฟ᮶࡞࠸ࡇ࡜ࡀᣲ ࡆࡽࢀࡿ㸬ࡑࡇ࡛ᮏ◊✲࡛ࡣ㸪 ᗘ࡜☢ሙࡢࢥࣥ ࢺ࣮ࣟࣝࡀ⡆౽࡟⾜࠼ࡿᮏᏛᡤ᭷ࡢ≀⌮≉ᛶホ౯ ⿦⨨_{PPMS㸦Quantum Deign ♫㸧ࢆ฼⏝ࡋ࡚㸪☢ሙ} ୰⇕⭾ᙇ ᐃࢩࢫࢸ࣒ࢆᵓ⠏ࡋࡓ㸬⌧ᅾ㸪_{5 ~ 300 K} ࡢ ᗘ⠊ᅖ࡛ ᗘ୍ᐃࡢୗ㸪☢ሙࢆኚ໬ࡉࡏࡓ᫬ ᅗ1 ࢫࣃࢵࢱἲࡢᶍᘧᅗ 㞵ᾏ ᭷భ㸪ሷᑼ Ὀᗈ㸪㕥ᮌ ᣅஓ㸪▼ཎ ᆂ㸪ᮧᒣ ⱱᖾ

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໬ྜ≀ࡸྜ㔠ࢆస〇ࡋ㸪ᇶ♏≀ᛶࡢホ౯࠿ࡽḟୡ ௦ࡢ㧗ᶵ⬟ᕼᅵ㢮㔠ᒓᮦᩱ࡜ࡋ࡚≉࡟㸪ᴟప ࠿ ࡽᐊ ⛬ᗘࡲ࡛౑⏝ ᗘᇦࢆព㆑ࡋࡓᮦᩱ࡬ࡢᒎ 㛤ࢆ┠ᣦࡍࡇ࡜ࢆ┠ⓗ࡜ࡋࡓ㸬  ࡇࢀࡲ࡛࡟Ce ࡜ᵝࠎ࡞ඖ⣲ࢆ⤌ࡳྜࢃࡏࡓ࢔ࣔ ࣝࣇ࢓ࢫ_{Ce ྜ㔠ࡀ࠸ࡃࡘ࠿స〇ࡉࢀ࡚࠸ࡿࡀ㸪ࡑ} ࡢ୰࡛ࡶᡃࠎࡀୡ⏺࡛ึࡵ࡚స〇ࡋࡓa-CexMn100-x ྜ㔠ࡣ㸪_{Ce ࡜ Mn ࡢ 2 ඖ㔠ᒓ㛫໬ྜ≀ࡀᏑᅾࡋ࡞} ࠸ࡓࡵ㸪࢔ࣔࣝࣇ࢓ࢫᵓ㐀ࡺ࠼࡟Ꮡᅾྍ⬟࡞ྜ㔠 ࡛࠶ࡿ㸬ࡇࡢ_{a-Ce-Mn ྜ㔠ࡢᇶ♏≀ᛶ ᐃࢆ⾜ࡗ} ࡓ㸬ࡑࡢ⤖ᯝ㸪a-Ce-Mn ྜ㔠ࡢ Ce ప⃰ᗘഃ࡛ࡣ㸪 ప ࡛ _{Mn ࣮࣓ࣔࣥࢺࡢ෾⤖࡟ࡼࡿࢫࣆࣥࢢࣛࢫ} ┦ࡀฟ⌧ࡋࡓ㸬Ce ⃰ᗘ x ࡀቑຍࡍࡿ࡜㸪ࢫࣆࣥࢢ ࣛࢫ㌿⛣ ᗘࡀῶᑡࡋ_{x = 60 ௜㏆࡛ᾘኻࡍࡿࠋCe} 㧗⃰ᗘഃ࡛ࡣ㸪Ce ࡢ 4f 㟁Ꮚ࡜ఏᑟ㟁Ꮚࡢΰᡂ㸦㏆ ⸨ຠᯝ㸧ࢆ㏻ࡋ㸪ᕧ኱࡞⇕ᐜ㔞ࢆᣢࡘ㔜࠸㟁Ꮚ≧ ែࡀᐇ⌧ࡍࡿ㸬ࡇࡢࡼ࠺࡟㸪⤌ᡂࡢኚ໬࡟కࡗ࡚ ≉ᛶࡀ㐃⥆ⓗ࡟ኚ໬ࡍࡿࡇ࡜ࡀࢃ࠿ࡗࡓ㸬(1-4)_ࡇࡢ ྜ㔠࡟࠾࠸࡚≉࡟⯆࿡῝࠸ᛶ㉁ࡣ㸪⇕⭾ᙇ࡛࠶ࡿ㸬 a-Ce-Mn ྜ㔠ࡢ⇕⭾ᙇࡣ㸪ᖜᗈ࠸⤌ᡂ⠊ᅖ࣭ ᗘ ⠊ᅖ࡛㏻ᖖ㔠ᒓࡼࡾᕧ኱࡛࠶ࡾ㸪≉࡟⤌ᡂࡀᣕᢠ ࡍࡿ_{x = 50 ࡛ࡣ㸪ᐊ ௜㏆࡛㖡ࡢಸ௨ୖࡢ⇕⭾ᙇ} ಀᩘࡀほ ࡉࢀࡿ࡜࡜ࡶ࡟㸪ప ࡛⇕⭾ᙇಀᩘࡀ ቑ኱ࡍࡿወጁ࡞ ᗘ౫Ꮡᛶࡀほ ࡉࢀࡓ㸬ࡑࡇ࡛㸪 ᮏࢱࢫࢡࡢ◊✲ㄢ㢟࡜ࡋ࡚ࡲࡎ㸪a-Ce-Mn ྜ㔠ࡢ ␗ᖖ࡞⇕⭾ᙇࢆゎ᫂ࡋ㸪࢔ࢡࢳ࢚࣮ࣗࢱ࣮⣲Ꮚ࡞ ࡝ࡢ⇕⭾ᙇࢆά࠿ࡋࡓᮦᩱ㛤Ⓨ࡟ᒎ㛤ࡍࡿࡇ࡜ࢆ ┠ᣦࡋࡓ㸬௒ᅇࡣ㸪⇕⭾ᙇ࡜⇕ຊᏛⓗ࡟㛵㐃ࡍࡿ ẚ⇕࡜㸪⇕⭾ᙇ࡟ᑐࡍࡿ☢ሙࡢຠᯝࢆ⤂௓ࡍࡿ㸬 2 ᐇ㦂 2㸬1 ヨᩱస〇 ヨᩱࡣ㸪_{DC 㧗㏿ࢫࣃࢵࢱἲࢆ⏝࠸࡚స〇ࡋࡓ㸬} ࢫࣃࢵࢱἲ࡜ࡣ㸪༙ᑟయⷧ⭷ࡸ㔠ᒓⷧ⭷ࡢస〇ἲ ࡢࡦ࡜ࡘ࡜ࡋ࡚Ⰻࡃ▱ࡽࢀࡓ᪉ἲ࡛࠶ࡿ㸬ᮏ◊✲ ࡛⏝࠸࡚࠸ࡿ_{DC 㧗㏿ࢫࣃࢵࢱἲࡣ㸪ẚ㍑ⓗ኱㠃✚} ࠿ࡘཌ࠸⭷_{(mm ࣮࢜ࢲ࣮)ࡢ㔠ᒓヨᩱస〇ࡀྍ⬟࡞} ࡓࡵ㸪୍ᗘࡢヨᩱస〇࡛ᵝࠎ࡞≀ᛶ ᐃࢆ⾜࠺ࡇ ࡜ࡀฟ᮶ࡿ㸬_{DC 㧗㏿ࢫࣃࢵࢱἲ࡟ࡼࡿ࢔ࣔࣝࣇ࢓} ࢫྜ㔠ࡢస〇ࣉࣟࢭࢫࡣ㸪ࡲࡎ㸪పᅽࡢAr ࢞ࢫ㞺 ᅖẼ୰ࡢࢳࣕࣥࣂ࣮ෆ࡟㸪ᑐྥࡋ࡚㓄⨨ࡉࢀࡓࣇ ࢕࣓ࣛࣥࢺ㟁ᴟ࡜࢔ࣀ࣮ࢻ㟁ᴟ㛫࡟㟁ᅽࢆ࠿ࡅ㸪 ࢢ࣮ࣟᨺ㟁࡟ࡼࡗ࡚ _{Ar ࢞ࢫࢆ㝧࢖࢜ࣥ໬ࡉࡏࡿ㸬} ࡑࡢᚋ㸪ࢱ࣮ࢤࢵࢺ㟁ᴟ࡟㈇ࡢ㧗㟁ᅽࢆ࠿ࡅࡿࡇ ࡜࡛㸪ࢱ࣮ࢤࢵࢺ㟁ᴟୖ࡟㓄⨨ࡉࢀࡓࢱ࣮ࢤࢵࢺ ྜ㔠࡟_Ar+_{࢖࢜ࣥࡀ⾪✺ࡋ㸪ࢱ࣮ࢤࢵࢺྜ㔠⾲㠃ࡢ} ཎᏊࡀࡣࡌࡁฟࡉࢀࡿ㸬ࡣࡌࡁฟࡉࢀࡓཎᏊࡣ㸪 ࢱ࣮ࢤࢵࢺྜ㔠┤ୖ࡟࠶ࡿỈ෭ࡉࢀࡓ㖡ᇶᯈ࡟⤖ ᬗ໬ࡏࡎሁ✚ࡍࡿࡓࡵ㸪⤖ᬗᵓ㐀ࢆᣢࡓ࡞࠸࢔ࣔ ࣝࣇ࢓ࢫྜ㔠ࡀᚓࡽࢀࡿ㸦ᅗ1㸧㸬 ࡲࡓ㸪ᮏ◊✲࡛ࡣ㸪ࢫࣃࢵࢱ࡟౑⏝ࡍࡿࢱ࣮ࢤ ࢵࢺྜ㔠ࢆࣔࣀ࢔࣮ࢡ⁐ゎ࡟ࡼࡗ࡚స〇ࡋ࡚࠸ࡿ㸬 ࢱ࣮ࢤࢵࢺྜ㔠ࢆ௵ពࡢ⤌ᡂẚ࡛స〇ࡍࡿࡇ࡜࡛ ࠾࠾ࡼࡑᚲせ࡜ࡍࡿ⤌ᡂẚࡢ࢔ࣔࣝࣇ࢓ࢫྜ㔠ࢆ స〇ࡍࡿࡇ࡜ࡀ࡛ࡁࡿࠋᚓࡽࢀࡓ࢔ࣔࣝࣇ࢓ࢫྜ 㔠ࡣ㸪ᶵᲔⓗ◊☻࡛㖡ᇶᯈࢆ㝖ཤࡋ㸪ྛ✀≀ᛶ  ᐃ⏝࡟ࢲ࢖࢔ࣔࣥࢻ࢝ࢵࢱ࣮࡛ᡂᙧࡋࡓ㸬 2㸬2 ヨᩱホ౯࠾ࡼࡧ≀ᛶ ᐃ ヨᩱࡢᵓ㐀ࡣ㸪X ⥺ᅇᢡ ᐃ࡟ࡼࡗ࡚☜ㄆࡋࡓ㸬 ⤌ᡂࡣ㸪_{ICP Ⓨගศගศᯒἲ࠾ࡼࡧ SEM-EDS ࡞࡝} ࢆ⏝࠸࡚☜ㄆࡋࡓ㸬  ≀ᛶ ᐃࡣ㸪☢໬⋡㸪㟁Ẽ᢬ᢠ㸪ẚ⇕㸪⇕⭾ᙇ ࠾ࡼࡧ⇕㟁⬟ࡢ ᗘ౫Ꮡᛶࢆ୰ᚰ࡟⾜࠸㸪ࡑࡢ☢ Ẽⓗᛶ㉁㸪ఏᑟ≉ᛶ㸪⇕≉ᛶ࡞࡝࠿ࡽ㟁Ꮚ≧ែ࡟ ࡘ࠸࡚⪃ᐹࡋࡓ㸬 ⇕⭾ᙇࡢ ᐃ᪉ἲࡣ㸪ࢫࢺࣞ࢖ࣥࢤ࣮ࢪἲࢆ⏝ ࠸ࡓ㸬ࢫࢺࣞ࢖ࣥࢤ࣮ࢪἲ࡜ࡣ㸪㔠ᒓ⟩࡛ฟ᮶ࡓ ṍࡳࢤ࣮ࢪࡢ㟁Ẽ᢬ᢠࡢኚ໬ࡀṍࡳࡢ㔞࡟ẚ౛ࡍ ࡿࡇ࡜ࢆ฼⏝ࡋࡓṍࡳࡢ ᐃἲ࡛࠶ࡿ㸬௨๓ࡲ࡛ ࡣ㸪ᴟప ෭෾⿦⨨ࢆ⏝࠸࡚㸪_{10 K ࠿ࡽᐊ ⛬ᗘ} ࡢ ᗘ⠊ᅖ࡛↓☢ሙࡢ ᐃࢆ⾜ࡗ࡚࠸ࡓࠋࡋ࠿ࡋ㸪 ࡇࡢ᪉ἲࡢḞⅬ࡜ࡋ࡚㸪ప ᇦࡢ ᗘ୙Ᏻᐃᛶ࠿ ࡽ௚ࡢ≀ᛶ ᐃ࡟ᑐࡋ㧗࠸ ᗘ࡛ࡢ ᐃ࡟࡞ࡗ࡚ ࠸ࡓࡇ࡜࡜↓☢ሙ࡛ࡢ ᐃࡋ࠿ฟ᮶࡞࠸ࡇ࡜ࡀᣲ ࡆࡽࢀࡿ㸬ࡑࡇ࡛ᮏ◊✲࡛ࡣ㸪 ᗘ࡜☢ሙࡢࢥࣥ ࢺ࣮ࣟࣝࡀ⡆౽࡟⾜࠼ࡿᮏᏛᡤ᭷ࡢ≀⌮≉ᛶホ౯ ⿦⨨PPMS㸦Quantum Deign ♫㸧ࢆ฼⏝ࡋ࡚㸪☢ሙ ୰⇕⭾ᙇ ᐃࢩࢫࢸ࣒ࢆᵓ⠏ࡋࡓ㸬⌧ᅾ㸪_{5 ~ 300 K} ࡢ ᗘ⠊ᅖ࡛ ᗘ୍ᐃࡢୗ㸪☢ሙࢆኚ໬ࡉࡏࡓ᫬ ᅗ_{1 ࢫࣃࢵࢱἲࡢᶍᘧᅗ} ᵓ㐀౫Ꮡᕼᅵ㢮ྜ㔠ࡢ㛤Ⓨ࡜☢Ẽ⇕㔞࣭⇕ᙎᛶᮦᩱ࡬ࡢᒎ㛤

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ࡢṍࡳࡢ ᐃࡀྍ⬟࡞☢ṍ ᐃࢩࢫࢸ࣒ࡢᵓ⠏࡟ ᡂຌࡋࡓ㸬௒ᅇࡣ㸪ᐊ ࠿ࡽప ࡲ࡛ᕧ኱࡞⇕⭾ ᙇࡀほ ࡉࢀࡿ_{x = 50 ࡢヨᩱ࡟ᑐࡋ☢ṍ ᐃࢆ⾜} ࡗࡓ㸬 ᐃ ᗘࡣ㸪_{5 K, 20 K, 50 K, 80 K, 100 K,} 150 K, 200 K, 275 K, 300 K㸪☢ሙࢆ 0 ~ 60 kOe ࡲ࡛ ኚ໬ࡉࡏ࡚☢ሙ᪉ྥ࡟ᑐࡍࡿṍࡳࡢ ᐃࢆ⾜ࡗࡓ㸬 3 ⤖ᯝ࡜⪃ᐹ 3㸬1 ẚ⇕ ᅗ_{2 ࡟ x = 50 ࡢẚ⇕ࡢ ᗘ౫Ꮡᛶࢆ♧ࡍ㸬୍⯡} ࡟☢ᛶయࡢẚ⇕ࡣ㸪᱁Ꮚẚ⇕ _Cph࡜☢Ẽẚ⇕ Cmag ࡜㟁Ꮚẚ⇕_Celࡢ࿴࡛ほ ࡉࢀࡿ㸬ᐇ㦂࡛ᚓࡽࢀࡓ ࢹ࣮ࢱ࡟ᑐࡋ㸪㐺ᙜ࡞ࢹࣂ࢖ ᗘࢆỴࡵ㸪ࢹࣂ࢖ 㛵ᩘ࡟ࡼࡗ࡚Cphࡢᐤ୚ࢆぢ✚ࡶࡗࡓ㸬ࢹࣂ࢖ ᗘ ࡣ㸪_{x = 50 ࡛ 300 K ࡜ࡋࡓ㸬ࡉࡽ࡟㸪ᚓࡽࢀࡓẚ⇕} ࠿ࡽ Cphࢆᘬࡃࡇ࡜࡛☢Ẽ࠾ࡼࡧ㟁Ꮚࡢᐤ୚ࢆぢ ✚ࡶࡗࡓ㸬㧗 ഃࡢẚ⇕ࡣ㸪ぢ✚ࡶࡗࡓ_Cph࡜ᐇ㦂 ್ࡀ࡯ࡰ୍⮴ࡍࡿࡇ࡜࠿ࡽ㸪᱁Ꮚẚ⇕ࡢᐤ୚ࡢࡳ ࡛ㄝ࡛᫂ࡁࡿ࠿ࡶࡋࢀ࡞࠸㸬_{150 K ௨ୗࡢప ࡛㸪} ☢Ẽ࠾ࡼࡧ㟁Ꮚẚ⇕ࡢᐤ୚ࡀ⌧ࢀ㸪40 ~ 50 K ௜㏆ ࡟ᒣࢆᣢࡘ㸬ప ẚ⇕ࡼࡾぢ✚ࡶࡽࢀࡓ㟁Ꮚẚ⇕ ಀᩘࡣ㸪x = 50 ࡛ 95.5 mJ/molK2࡜㏻ᖖ㔠ᒓ࡟ẚ࡭ ࡚࠾ࡼࡑ_{100 ಸࡶ኱ࡁ࠸㸬} 3㸬2 ⇕⭾ᙇ ᅗ_{3 ࡟ a-Ce-Mn ྜ㔠ࡢ⥺⭾ᙇL/L ࡢ ᗘ౫Ꮡᛶ} ࢆ♧ࡍ㸬ẚ㍑ࡢࡓࡵ㸪_{Cu ࡢ⥺⭾ᙇࡢ ᗘ౫Ꮡᛶࡶ} ♧ࡍ㸬L/L ࡣ㸪ࡍ࡭࡚ࡢ⤌ᡂ࡟࠾࠸࡚ Cu ࡜ẚ㍑ ࡋ࡚኱ࡁ࠸ ᗘ౫Ꮡࢆ♧ࡍ㸬_{Ce ప⃰ᗘഃ࡛㏻ᖖ㔠} ᒓྠᵝ࡟ ᗘࡢῶᑡ࡜࡜ࡶ࡟ୗ࡟ฝࡢ ᗘ౫Ꮡࢆ ♧ࡍ㸬_{Ce ⃰ᗘ 50 at%௨ୖ࡛ࡣ㸪100 K ௜㏆ࡲ࡛⥺} ᙧⓗ࡞ῶᑡࢆ♧ࡋ㸪ࡑࡢᚋୖ࡟ฝࡢ ᗘ౫Ꮡࢆ♧ ࡍ㸬ᅗ4 ࡟ a-Ce-Mn ྜ㔠ࡢ⇕⭾ᙇಀᩘࡢ ᗘ౫Ꮡ ᛶࢆ♧ࡍ㸬ࡣ㸪_{Ce ⃰ᗘ 50 at%௨ୗࡢ㧗 ഃ࡛㏻} ᖖ㔠ᒓ࡟ẚ࡭_{2㹼3 ಸࡶࡢ್ࢆ♧ࡍ㸬ࡲࡓ㸪50 at%} ௨ୖ࡛ࡣ㸪ᖜᗈ࠸ ᗘ㡿ᇦ࡛ᕧ኱࡞್ࢆ♧ࡍ㸬₁₀₀ K ௨ୗࡢప ഃ࡛ࡣ㸪 ᗘࡢῶᑡ࡜࡜ࡶ࡟኱ࡁ࡞ ቑ኱ࢆ♧ࡋ㸪ࡑࡢᚋࣆ࣮ࢡࢆᣢࡗ࡚኱ࡁࡃῶᑡࡍ ࡿ㸬ప ࡢࡢቑ኱ࡣ㸪☢Ẽẚ⇕ࡢቑ኱࡜࠾࠾ࡼࡑ ୍⮴ࡋ࡚࠸ࡿ㸬ࡇࡢቑ኱ࡣ㸪a-(Ce,Y)-Mn ྜ㔠ࡢ◊ ✲(5)࠿ࡽ㸪㏆⸨ຠᯝ࡟ࡼࡿࡶࡢ࡜⪃࠼ࡽࢀ࡚࠸ࡿ㸬 ᅗ5 ࡟ a-Ce-Mn ྜ㔠ࡢ☢ṍࡢ☢ሙ౫Ꮡᛶࢆ♧ࡍ㸬 ࡍ࡭࡚ࡢ ᗘ࡟࠾࠸࡚㸪㈇ࡢ☢ṍࡀほ ࡉࢀࡓ㸬 ࡇࢀࡣ☢ሙ࡟ࡼࡗ࡚⇕⭾ᙇࡀᢚไࡉࢀࡓࡇ࡜ࢆ♧ ࡋ࡚࠸ࡿ㸬ࡲࡓ㸪㧗 ࣭ప☢ሙ࡛ࡣ㸪☢ሙ࡟࡯࡜ ࢇ࡝౫Ꮡࡋ࡞࠸ࡀ㸪ప ࣭㧗☢ሙ࡯࡝኱ࡁ࡞☢ሙ ౫Ꮡᛶࡀほ ࡉࢀࡓ㸬ᅗ_{6 ࡟ a-Ce-Mn ྜ㔠ࡢ☢ṍ} ࡢ ᗘ౫Ꮡᛶࢆ♧ࡍ㸬ప☢ሙഃ࡛ࡣ㸪࡯࡜ࢇ࡝  ᗘ࡟౫Ꮡࡋ࡞࠸ࡢ࡟ᑐࡋ㸪_{30 kOe ௨ୖࡢ☢ሙ࡛㸪} 100 K ௨ୗࡢప ࡛ ᗘࡢῶᑡ࡜࡜ࡶ࡟኱ࡁࡃῶ ᅗ_{2 x = 50 ࡢẚ⇕ࡢ ᗘ౫Ꮡᛶ} ᅗ_{3 a-Ce-Mn ྜ㔠ࡢ⥺⭾ᙇL/L ࡢ}  ᗘ౫Ꮡᛶ ᅗ4 a-Ce-Mn ྜ㔠ࡢ⇕⭾ᙇಀᩘࡢ  ᗘ౫Ꮡᛶ ᵓ㐀౫Ꮡᕼᅵ㢮ྜ㔠ࡢ㛤Ⓨ࡜☢Ẽ⇕㔞࣭⇕ᙎᛶᮦᩱ࡬ࡢᒎ㛤

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ࡢṍࡳࡢ ᐃࡀྍ⬟࡞☢ṍ ᐃࢩࢫࢸ࣒ࡢᵓ⠏࡟ ᡂຌࡋࡓ㸬௒ᅇࡣ㸪ᐊ ࠿ࡽప ࡲ࡛ᕧ኱࡞⇕⭾ ᙇࡀほ ࡉࢀࡿx = 50 ࡢヨᩱ࡟ᑐࡋ☢ṍ ᐃࢆ⾜ ࡗࡓ㸬 ᐃ ᗘࡣ㸪_{5 K, 20 K, 50 K, 80 K, 100 K,} 150 K, 200 K, 275 K, 300 K㸪☢ሙࢆ 0 ~ 60 kOe ࡲ࡛ ኚ໬ࡉࡏ࡚☢ሙ᪉ྥ࡟ᑐࡍࡿṍࡳࡢ ᐃࢆ⾜ࡗࡓ㸬 3 ⤖ᯝ࡜⪃ᐹ 3㸬1 ẚ⇕ ᅗ_{2 ࡟ x = 50 ࡢẚ⇕ࡢ ᗘ౫Ꮡᛶࢆ♧ࡍ㸬୍⯡} ࡟☢ᛶయࡢẚ⇕ࡣ㸪᱁Ꮚẚ⇕ _Cph࡜☢Ẽẚ⇕ _Cmag ࡜㟁Ꮚẚ⇕Celࡢ࿴࡛ほ ࡉࢀࡿ㸬ᐇ㦂࡛ᚓࡽࢀࡓ ࢹ࣮ࢱ࡟ᑐࡋ㸪㐺ᙜ࡞ࢹࣂ࢖ ᗘࢆỴࡵ㸪ࢹࣂ࢖ 㛵ᩘ࡟ࡼࡗ࡚Cphࡢᐤ୚ࢆぢ✚ࡶࡗࡓ㸬ࢹࣂ࢖ ᗘ ࡣ㸪_{x = 50 ࡛ 300 K ࡜ࡋࡓ㸬ࡉࡽ࡟㸪ᚓࡽࢀࡓẚ⇕} ࠿ࡽ Cphࢆᘬࡃࡇ࡜࡛☢Ẽ࠾ࡼࡧ㟁Ꮚࡢᐤ୚ࢆぢ ✚ࡶࡗࡓ㸬㧗 ഃࡢẚ⇕ࡣ㸪ぢ✚ࡶࡗࡓ_Cph࡜ᐇ㦂 ್ࡀ࡯ࡰ୍⮴ࡍࡿࡇ࡜࠿ࡽ㸪᱁Ꮚẚ⇕ࡢᐤ୚ࡢࡳ ࡛ㄝ࡛᫂ࡁࡿ࠿ࡶࡋࢀ࡞࠸㸬_{150 K ௨ୗࡢప ࡛㸪} ☢Ẽ࠾ࡼࡧ㟁Ꮚẚ⇕ࡢᐤ୚ࡀ⌧ࢀ㸪_{40 ~ 50 K ௜㏆} ࡟ᒣࢆᣢࡘ㸬ప ẚ⇕ࡼࡾぢ✚ࡶࡽࢀࡓ㟁Ꮚẚ⇕ ಀᩘࡣ㸪x = 50 ࡛ 95.5 mJ/molK2_{࡜㏻ᖖ㔠ᒓ࡟ẚ࡭} ࡚࠾ࡼࡑ_{100 ಸࡶ኱ࡁ࠸㸬} 3㸬2 ⇕⭾ᙇ ᅗ3 ࡟ a-Ce-Mn ྜ㔠ࡢ⥺⭾ᙇL/L ࡢ ᗘ౫Ꮡᛶ ࢆ♧ࡍ㸬ẚ㍑ࡢࡓࡵ㸪_{Cu ࡢ⥺⭾ᙇࡢ ᗘ౫Ꮡᛶࡶ} ♧ࡍ㸬L/L ࡣ㸪ࡍ࡭࡚ࡢ⤌ᡂ࡟࠾࠸࡚ Cu ࡜ẚ㍑ ࡋ࡚኱ࡁ࠸ ᗘ౫Ꮡࢆ♧ࡍ㸬Ce ప⃰ᗘഃ࡛㏻ᖖ㔠 ᒓྠᵝ࡟ ᗘࡢῶᑡ࡜࡜ࡶ࡟ୗ࡟ฝࡢ ᗘ౫Ꮡࢆ ♧ࡍ㸬_{Ce ⃰ᗘ 50 at%௨ୖ࡛ࡣ㸪100 K ௜㏆ࡲ࡛⥺} ᙧⓗ࡞ῶᑡࢆ♧ࡋ㸪ࡑࡢᚋୖ࡟ฝࡢ ᗘ౫Ꮡࢆ♧ ࡍ㸬ᅗ_{4 ࡟ a-Ce-Mn ྜ㔠ࡢ⇕⭾ᙇಀᩘ}ࡢ ᗘ౫Ꮡ ᛶࢆ♧ࡍ㸬ࡣ㸪_{Ce ⃰ᗘ 50 at%௨ୗࡢ㧗 ഃ࡛㏻} ᖖ㔠ᒓ࡟ẚ࡭_{2㹼3 ಸࡶࡢ್ࢆ♧ࡍ㸬ࡲࡓ㸪50 at%} ௨ୖ࡛ࡣ㸪ᖜᗈ࠸ ᗘ㡿ᇦ࡛ᕧ኱࡞್ࢆ♧ࡍ㸬100 K ௨ୗࡢప ഃ࡛ࡣ㸪 ᗘࡢῶᑡ࡜࡜ࡶ࡟኱ࡁ࡞ ቑ኱ࢆ♧ࡋ㸪ࡑࡢᚋࣆ࣮ࢡࢆᣢࡗ࡚኱ࡁࡃῶᑡࡍ ࡿ㸬ప ࡢࡢቑ኱ࡣ㸪☢Ẽẚ⇕ࡢቑ኱࡜࠾࠾ࡼࡑ ୍⮴ࡋ࡚࠸ࡿ㸬ࡇࡢቑ኱ࡣ㸪a-(Ce,Y)-Mn ྜ㔠ࡢ◊ ✲(5)_{࠿ࡽ㸪㏆⸨ຠᯝ࡟ࡼࡿࡶࡢ࡜⪃࠼ࡽࢀ࡚࠸ࡿ㸬} ᅗ_{5 ࡟ a-Ce-Mn ྜ㔠ࡢ☢ṍࡢ☢ሙ౫Ꮡᛶࢆ♧ࡍ㸬} ࡍ࡭࡚ࡢ ᗘ࡟࠾࠸࡚㸪㈇ࡢ☢ṍࡀほ ࡉࢀࡓ㸬 ࡇࢀࡣ☢ሙ࡟ࡼࡗ࡚⇕⭾ᙇࡀᢚไࡉࢀࡓࡇ࡜ࢆ♧ ࡋ࡚࠸ࡿ㸬ࡲࡓ㸪㧗 ࣭ప☢ሙ࡛ࡣ㸪☢ሙ࡟࡯࡜ ࢇ࡝౫Ꮡࡋ࡞࠸ࡀ㸪ప ࣭㧗☢ሙ࡯࡝኱ࡁ࡞☢ሙ ౫Ꮡᛶࡀほ ࡉࢀࡓ㸬ᅗ_{6 ࡟ a-Ce-Mn ྜ㔠ࡢ☢ṍ} ࡢ ᗘ౫Ꮡᛶࢆ♧ࡍ㸬ప☢ሙഃ࡛ࡣ㸪࡯࡜ࢇ࡝  ᗘ࡟౫Ꮡࡋ࡞࠸ࡢ࡟ᑐࡋ㸪_{30 kOe ௨ୖࡢ☢ሙ࡛㸪} 100 K ௨ୗࡢప ࡛ ᗘࡢῶᑡ࡜࡜ࡶ࡟኱ࡁࡃῶ ᅗ_{2 x = 50 ࡢẚ⇕ࡢ ᗘ౫Ꮡᛶ} ᅗ_{3 a-Ce-Mn ྜ㔠ࡢ⥺⭾ᙇL/L ࡢ}  ᗘ౫Ꮡᛶ ᅗ_{4 a-Ce-Mn ྜ㔠ࡢ⇕⭾ᙇಀᩘ}ࡢ  ᗘ౫Ꮡᛶ

－　39　－ 㞵ᾏ ᭷భ㸪ሷᑼ Ὀᗈ㸪㕥ᮌ ᣅஓ㸪▼ཎ ᆂ㸪ᮧᒣ ⱱᖾ

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໬ྜ≀ࡸྜ㔠ࢆస〇ࡋ㸪ᇶ♏≀ᛶࡢホ౯࠿ࡽḟୡ ௦ࡢ㧗ᶵ⬟ᕼᅵ㢮㔠ᒓᮦᩱ࡜ࡋ࡚≉࡟㸪ᴟప ࠿ ࡽᐊ ⛬ᗘࡲ࡛౑⏝ ᗘᇦࢆព㆑ࡋࡓᮦᩱ࡬ࡢᒎ 㛤ࢆ┠ᣦࡍࡇ࡜ࢆ┠ⓗ࡜ࡋࡓ㸬  ࡇࢀࡲ࡛࡟_{Ce ࡜ᵝࠎ࡞ඖ⣲ࢆ⤌ࡳྜࢃࡏࡓ࢔ࣔ} ࣝࣇ࢓ࢫ_{Ce ྜ㔠ࡀ࠸ࡃࡘ࠿స〇ࡉࢀ࡚࠸ࡿࡀ㸪ࡑ} ࡢ୰࡛ࡶᡃࠎࡀୡ⏺࡛ึࡵ࡚స〇ࡋࡓ_a-CexMn100-x ྜ㔠ࡣ㸪_{Ce ࡜ Mn ࡢ 2 ඖ㔠ᒓ㛫໬ྜ≀ࡀᏑᅾࡋ࡞} ࠸ࡓࡵ㸪࢔ࣔࣝࣇ࢓ࢫᵓ㐀ࡺ࠼࡟Ꮡᅾྍ⬟࡞ྜ㔠 ࡛࠶ࡿ㸬ࡇࡢa-Ce-Mn ྜ㔠ࡢᇶ♏≀ᛶ ᐃࢆ⾜ࡗ ࡓ㸬ࡑࡢ⤖ᯝ㸪_{a-Ce-Mn ྜ㔠ࡢ Ce ప⃰ᗘഃ࡛ࡣ㸪} ప ࡛ _{Mn ࣮࣓ࣔࣥࢺࡢ෾⤖࡟ࡼࡿࢫࣆࣥࢢࣛࢫ} ┦ࡀฟ⌧ࡋࡓ㸬_{Ce ⃰ᗘ x ࡀቑຍࡍࡿ࡜㸪ࢫࣆࣥࢢ} ࣛࢫ㌿⛣ ᗘࡀῶᑡࡋx = 60 ௜㏆࡛ᾘኻࡍࡿࠋCe 㧗⃰ᗘഃ࡛ࡣ㸪_{Ce ࡢ 4f 㟁Ꮚ࡜ఏᑟ㟁Ꮚࡢΰᡂ㸦㏆} ⸨ຠᯝ㸧ࢆ㏻ࡋ㸪ᕧ኱࡞⇕ᐜ㔞ࢆᣢࡘ㔜࠸㟁Ꮚ≧ ែࡀᐇ⌧ࡍࡿ㸬ࡇࡢࡼ࠺࡟㸪⤌ᡂࡢኚ໬࡟కࡗ࡚ ≉ᛶࡀ㐃⥆ⓗ࡟ኚ໬ࡍࡿࡇ࡜ࡀࢃ࠿ࡗࡓ㸬(1-4)_ࡇࡢ ྜ㔠࡟࠾࠸࡚≉࡟⯆࿡῝࠸ᛶ㉁ࡣ㸪⇕⭾ᙇ࡛࠶ࡿ㸬 a-Ce-Mn ྜ㔠ࡢ⇕⭾ᙇࡣ㸪ᖜᗈ࠸⤌ᡂ⠊ᅖ࣭ ᗘ ⠊ᅖ࡛㏻ᖖ㔠ᒓࡼࡾᕧ኱࡛࠶ࡾ㸪≉࡟⤌ᡂࡀᣕᢠ ࡍࡿx = 50 ࡛ࡣ㸪ᐊ ௜㏆࡛㖡ࡢಸ௨ୖࡢ⇕⭾ᙇ ಀᩘࡀほ ࡉࢀࡿ࡜࡜ࡶ࡟㸪ప ࡛⇕⭾ᙇಀᩘࡀ ቑ኱ࡍࡿወጁ࡞ ᗘ౫Ꮡᛶࡀほ ࡉࢀࡓ㸬ࡑࡇ࡛㸪 ᮏࢱࢫࢡࡢ◊✲ㄢ㢟࡜ࡋ࡚ࡲࡎ㸪_{a-Ce-Mn ྜ㔠ࡢ} ␗ᖖ࡞⇕⭾ᙇࢆゎ᫂ࡋ㸪࢔ࢡࢳ࢚࣮ࣗࢱ࣮⣲Ꮚ࡞ ࡝ࡢ⇕⭾ᙇࢆά࠿ࡋࡓᮦᩱ㛤Ⓨ࡟ᒎ㛤ࡍࡿࡇ࡜ࢆ ┠ᣦࡋࡓ㸬௒ᅇࡣ㸪⇕⭾ᙇ࡜⇕ຊᏛⓗ࡟㛵㐃ࡍࡿ ẚ⇕࡜㸪⇕⭾ᙇ࡟ᑐࡍࡿ☢ሙࡢຠᯝࢆ⤂௓ࡍࡿ㸬 2 ᐇ㦂 2㸬1 ヨᩱస〇 ヨᩱࡣ㸪_{DC 㧗㏿ࢫࣃࢵࢱἲࢆ⏝࠸࡚స〇ࡋࡓ㸬} ࢫࣃࢵࢱἲ࡜ࡣ㸪༙ᑟయⷧ⭷ࡸ㔠ᒓⷧ⭷ࡢస〇ἲ ࡢࡦ࡜ࡘ࡜ࡋ࡚Ⰻࡃ▱ࡽࢀࡓ᪉ἲ࡛࠶ࡿ㸬ᮏ◊✲ ࡛⏝࠸࡚࠸ࡿ_{DC 㧗㏿ࢫࣃࢵࢱἲࡣ㸪ẚ㍑ⓗ኱㠃✚} ࠿ࡘཌ࠸⭷_{(mm ࣮࢜ࢲ࣮)ࡢ㔠ᒓヨᩱస〇ࡀྍ⬟࡞} ࡓࡵ㸪୍ᗘࡢヨᩱస〇࡛ᵝࠎ࡞≀ᛶ ᐃࢆ⾜࠺ࡇ ࡜ࡀฟ᮶ࡿ㸬_{DC 㧗㏿ࢫࣃࢵࢱἲ࡟ࡼࡿ࢔ࣔࣝࣇ࢓} ࢫྜ㔠ࡢస〇ࣉࣟࢭࢫࡣ㸪ࡲࡎ㸪పᅽࡢ_{Ar ࢞ࢫ㞺} ᅖẼ୰ࡢࢳࣕࣥࣂ࣮ෆ࡟㸪ᑐྥࡋ࡚㓄⨨ࡉࢀࡓࣇ ࢕࣓ࣛࣥࢺ㟁ᴟ࡜࢔ࣀ࣮ࢻ㟁ᴟ㛫࡟㟁ᅽࢆ࠿ࡅ㸪 ࢢ࣮ࣟᨺ㟁࡟ࡼࡗ࡚ _{Ar ࢞ࢫࢆ㝧࢖࢜ࣥ໬ࡉࡏࡿ㸬} ࡑࡢᚋ㸪ࢱ࣮ࢤࢵࢺ㟁ᴟ࡟㈇ࡢ㧗㟁ᅽࢆ࠿ࡅࡿࡇ ࡜࡛㸪ࢱ࣮ࢤࢵࢺ㟁ᴟୖ࡟㓄⨨ࡉࢀࡓࢱ࣮ࢤࢵࢺ ྜ㔠࡟_Ar+_{࢖࢜ࣥࡀ⾪✺ࡋ㸪ࢱ࣮ࢤࢵࢺྜ㔠⾲㠃ࡢ} ཎᏊࡀࡣࡌࡁฟࡉࢀࡿ㸬ࡣࡌࡁฟࡉࢀࡓཎᏊࡣ㸪 ࢱ࣮ࢤࢵࢺྜ㔠┤ୖ࡟࠶ࡿỈ෭ࡉࢀࡓ㖡ᇶᯈ࡟⤖ ᬗ໬ࡏࡎሁ✚ࡍࡿࡓࡵ㸪⤖ᬗᵓ㐀ࢆᣢࡓ࡞࠸࢔ࣔ ࣝࣇ࢓ࢫྜ㔠ࡀᚓࡽࢀࡿ㸦ᅗ_1㸧㸬 ࡲࡓ㸪ᮏ◊✲࡛ࡣ㸪ࢫࣃࢵࢱ࡟౑⏝ࡍࡿࢱ࣮ࢤ ࢵࢺྜ㔠ࢆࣔࣀ࢔࣮ࢡ⁐ゎ࡟ࡼࡗ࡚స〇ࡋ࡚࠸ࡿ㸬 ࢱ࣮ࢤࢵࢺྜ㔠ࢆ௵ពࡢ⤌ᡂẚ࡛స〇ࡍࡿࡇ࡜࡛ ࠾࠾ࡼࡑᚲせ࡜ࡍࡿ⤌ᡂẚࡢ࢔ࣔࣝࣇ࢓ࢫྜ㔠ࢆ స〇ࡍࡿࡇ࡜ࡀ࡛ࡁࡿࠋᚓࡽࢀࡓ࢔ࣔࣝࣇ࢓ࢫྜ 㔠ࡣ㸪ᶵᲔⓗ◊☻࡛㖡ᇶᯈࢆ㝖ཤࡋ㸪ྛ✀≀ᛶ  ᐃ⏝࡟ࢲ࢖࢔ࣔࣥࢻ࢝ࢵࢱ࣮࡛ᡂᙧࡋࡓ㸬 2㸬2 ヨᩱホ౯࠾ࡼࡧ≀ᛶ ᐃ ヨᩱࡢᵓ㐀ࡣ㸪_{X ⥺ᅇᢡ ᐃ࡟ࡼࡗ࡚☜ㄆࡋࡓ㸬} ⤌ᡂࡣ㸪_{ICP Ⓨගศගศᯒἲ࠾ࡼࡧ SEM-EDS ࡞࡝} ࢆ⏝࠸࡚☜ㄆࡋࡓ㸬  ≀ᛶ ᐃࡣ㸪☢໬⋡㸪㟁Ẽ᢬ᢠ㸪ẚ⇕㸪⇕⭾ᙇ ࠾ࡼࡧ⇕㟁⬟ࡢ ᗘ౫Ꮡᛶࢆ୰ᚰ࡟⾜࠸㸪ࡑࡢ☢ Ẽⓗᛶ㉁㸪ఏᑟ≉ᛶ㸪⇕≉ᛶ࡞࡝࠿ࡽ㟁Ꮚ≧ែ࡟ ࡘ࠸࡚⪃ᐹࡋࡓ㸬 ⇕⭾ᙇࡢ ᐃ᪉ἲࡣ㸪ࢫࢺࣞ࢖ࣥࢤ࣮ࢪἲࢆ⏝ ࠸ࡓ㸬ࢫࢺࣞ࢖ࣥࢤ࣮ࢪἲ࡜ࡣ㸪㔠ᒓ⟩࡛ฟ᮶ࡓ ṍࡳࢤ࣮ࢪࡢ㟁Ẽ᢬ᢠࡢኚ໬ࡀṍࡳࡢ㔞࡟ẚ౛ࡍ ࡿࡇ࡜ࢆ฼⏝ࡋࡓṍࡳࡢ ᐃἲ࡛࠶ࡿ㸬௨๓ࡲ࡛ ࡣ㸪ᴟప ෭෾⿦⨨ࢆ⏝࠸࡚㸪_{10 K ࠿ࡽᐊ ⛬ᗘ} ࡢ ᗘ⠊ᅖ࡛↓☢ሙࡢ ᐃࢆ⾜ࡗ࡚࠸ࡓࠋࡋ࠿ࡋ㸪 ࡇࡢ᪉ἲࡢḞⅬ࡜ࡋ࡚㸪ప ᇦࡢ ᗘ୙Ᏻᐃᛶ࠿ ࡽ௚ࡢ≀ᛶ ᐃ࡟ᑐࡋ㧗࠸ ᗘ࡛ࡢ ᐃ࡟࡞ࡗ࡚ ࠸ࡓࡇ࡜࡜↓☢ሙ࡛ࡢ ᐃࡋ࠿ฟ᮶࡞࠸ࡇ࡜ࡀᣲ ࡆࡽࢀࡿ㸬ࡑࡇ࡛ᮏ◊✲࡛ࡣ㸪 ᗘ࡜☢ሙࡢࢥࣥ ࢺ࣮ࣟࣝࡀ⡆౽࡟⾜࠼ࡿᮏᏛᡤ᭷ࡢ≀⌮≉ᛶホ౯ ⿦⨨_{PPMS㸦Quantum Deign ♫㸧ࢆ฼⏝ࡋ࡚㸪☢ሙ} ୰⇕⭾ᙇ ᐃࢩࢫࢸ࣒ࢆᵓ⠏ࡋࡓ㸬⌧ᅾ㸪_{5 ~ 300 K} ࡢ ᗘ⠊ᅖ࡛ ᗘ୍ᐃࡢୗ㸪☢ሙࢆኚ໬ࡉࡏࡓ᫬ ᅗ1 ࢫࣃࢵࢱἲࡢᶍᘧᅗ 㞵ᾏ ᭷భ㸪ሷᑼ Ὀᗈ㸪㕥ᮌ ᣅஓ㸪▼ཎ ᆂ㸪ᮧᒣ ⱱᖾ

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໬ྜ≀ࡸྜ㔠ࢆస〇ࡋ㸪ᇶ♏≀ᛶࡢホ౯࠿ࡽḟୡ ௦ࡢ㧗ᶵ⬟ᕼᅵ㢮㔠ᒓᮦᩱ࡜ࡋ࡚≉࡟㸪ᴟప ࠿ ࡽᐊ ⛬ᗘࡲ࡛౑⏝ ᗘᇦࢆព㆑ࡋࡓᮦᩱ࡬ࡢᒎ 㛤ࢆ┠ᣦࡍࡇ࡜ࢆ┠ⓗ࡜ࡋࡓ㸬  ࡇࢀࡲ࡛࡟Ce ࡜ᵝࠎ࡞ඖ⣲ࢆ⤌ࡳྜࢃࡏࡓ࢔ࣔ ࣝࣇ࢓ࢫ_{Ce ྜ㔠ࡀ࠸ࡃࡘ࠿స〇ࡉࢀ࡚࠸ࡿࡀ㸪ࡑ} ࡢ୰࡛ࡶᡃࠎࡀୡ⏺࡛ึࡵ࡚స〇ࡋࡓa-CexMn100-x ྜ㔠ࡣ㸪_{Ce ࡜ Mn ࡢ 2 ඖ㔠ᒓ㛫໬ྜ≀ࡀᏑᅾࡋ࡞} ࠸ࡓࡵ㸪࢔ࣔࣝࣇ࢓ࢫᵓ㐀ࡺ࠼࡟Ꮡᅾྍ⬟࡞ྜ㔠 ࡛࠶ࡿ㸬ࡇࡢ_{a-Ce-Mn ྜ㔠ࡢᇶ♏≀ᛶ ᐃࢆ⾜ࡗ} ࡓ㸬ࡑࡢ⤖ᯝ㸪a-Ce-Mn ྜ㔠ࡢ Ce ప⃰ᗘഃ࡛ࡣ㸪 ప ࡛ _{Mn ࣮࣓ࣔࣥࢺࡢ෾⤖࡟ࡼࡿࢫࣆࣥࢢࣛࢫ} ┦ࡀฟ⌧ࡋࡓ㸬Ce ⃰ᗘ x ࡀቑຍࡍࡿ࡜㸪ࢫࣆࣥࢢ ࣛࢫ㌿⛣ ᗘࡀῶᑡࡋ_{x = 60 ௜㏆࡛ᾘኻࡍࡿࠋCe} 㧗⃰ᗘഃ࡛ࡣ㸪Ce ࡢ 4f 㟁Ꮚ࡜ఏᑟ㟁Ꮚࡢΰᡂ㸦㏆ ⸨ຠᯝ㸧ࢆ㏻ࡋ㸪ᕧ኱࡞⇕ᐜ㔞ࢆᣢࡘ㔜࠸㟁Ꮚ≧ ែࡀᐇ⌧ࡍࡿ㸬ࡇࡢࡼ࠺࡟㸪⤌ᡂࡢኚ໬࡟కࡗ࡚ ≉ᛶࡀ㐃⥆ⓗ࡟ኚ໬ࡍࡿࡇ࡜ࡀࢃ࠿ࡗࡓ㸬(1-4)_ࡇࡢ ྜ㔠࡟࠾࠸࡚≉࡟⯆࿡῝࠸ᛶ㉁ࡣ㸪⇕⭾ᙇ࡛࠶ࡿ㸬 a-Ce-Mn ྜ㔠ࡢ⇕⭾ᙇࡣ㸪ᖜᗈ࠸⤌ᡂ⠊ᅖ࣭ ᗘ ⠊ᅖ࡛㏻ᖖ㔠ᒓࡼࡾᕧ኱࡛࠶ࡾ㸪≉࡟⤌ᡂࡀᣕᢠ ࡍࡿ_{x = 50 ࡛ࡣ㸪ᐊ ௜㏆࡛㖡ࡢಸ௨ୖࡢ⇕⭾ᙇ} ಀᩘࡀほ ࡉࢀࡿ࡜࡜ࡶ࡟㸪ప ࡛⇕⭾ᙇಀᩘࡀ ቑ኱ࡍࡿወጁ࡞ ᗘ౫Ꮡᛶࡀほ ࡉࢀࡓ㸬ࡑࡇ࡛㸪 ᮏࢱࢫࢡࡢ◊✲ㄢ㢟࡜ࡋ࡚ࡲࡎ㸪a-Ce-Mn ྜ㔠ࡢ ␗ᖖ࡞⇕⭾ᙇࢆゎ᫂ࡋ㸪࢔ࢡࢳ࢚࣮ࣗࢱ࣮⣲Ꮚ࡞ ࡝ࡢ⇕⭾ᙇࢆά࠿ࡋࡓᮦᩱ㛤Ⓨ࡟ᒎ㛤ࡍࡿࡇ࡜ࢆ ┠ᣦࡋࡓ㸬௒ᅇࡣ㸪⇕⭾ᙇ࡜⇕ຊᏛⓗ࡟㛵㐃ࡍࡿ ẚ⇕࡜㸪⇕⭾ᙇ࡟ᑐࡍࡿ☢ሙࡢຠᯝࢆ⤂௓ࡍࡿ㸬 2 ᐇ㦂 2㸬1 ヨᩱస〇 ヨᩱࡣ㸪_{DC 㧗㏿ࢫࣃࢵࢱἲࢆ⏝࠸࡚స〇ࡋࡓ㸬} ࢫࣃࢵࢱἲ࡜ࡣ㸪༙ᑟయⷧ⭷ࡸ㔠ᒓⷧ⭷ࡢస〇ἲ ࡢࡦ࡜ࡘ࡜ࡋ࡚Ⰻࡃ▱ࡽࢀࡓ᪉ἲ࡛࠶ࡿ㸬ᮏ◊✲ ࡛⏝࠸࡚࠸ࡿ_{DC 㧗㏿ࢫࣃࢵࢱἲࡣ㸪ẚ㍑ⓗ኱㠃✚} ࠿ࡘཌ࠸⭷_{(mm ࣮࢜ࢲ࣮)ࡢ㔠ᒓヨᩱస〇ࡀྍ⬟࡞} ࡓࡵ㸪୍ᗘࡢヨᩱస〇࡛ᵝࠎ࡞≀ᛶ ᐃࢆ⾜࠺ࡇ ࡜ࡀฟ᮶ࡿ㸬_{DC 㧗㏿ࢫࣃࢵࢱἲ࡟ࡼࡿ࢔ࣔࣝࣇ࢓} ࢫྜ㔠ࡢస〇ࣉࣟࢭࢫࡣ㸪ࡲࡎ㸪పᅽࡢAr ࢞ࢫ㞺 ᅖẼ୰ࡢࢳࣕࣥࣂ࣮ෆ࡟㸪ᑐྥࡋ࡚㓄⨨ࡉࢀࡓࣇ ࢕࣓ࣛࣥࢺ㟁ᴟ࡜࢔ࣀ࣮ࢻ㟁ᴟ㛫࡟㟁ᅽࢆ࠿ࡅ㸪 ࢢ࣮ࣟᨺ㟁࡟ࡼࡗ࡚ _{Ar ࢞ࢫࢆ㝧࢖࢜ࣥ໬ࡉࡏࡿ㸬} ࡑࡢᚋ㸪ࢱ࣮ࢤࢵࢺ㟁ᴟ࡟㈇ࡢ㧗㟁ᅽࢆ࠿ࡅࡿࡇ ࡜࡛㸪ࢱ࣮ࢤࢵࢺ㟁ᴟୖ࡟㓄⨨ࡉࢀࡓࢱ࣮ࢤࢵࢺ ྜ㔠࡟_Ar+_{࢖࢜ࣥࡀ⾪✺ࡋ㸪ࢱ࣮ࢤࢵࢺྜ㔠⾲㠃ࡢ} ཎᏊࡀࡣࡌࡁฟࡉࢀࡿ㸬ࡣࡌࡁฟࡉࢀࡓཎᏊࡣ㸪 ࢱ࣮ࢤࢵࢺྜ㔠┤ୖ࡟࠶ࡿỈ෭ࡉࢀࡓ㖡ᇶᯈ࡟⤖ ᬗ໬ࡏࡎሁ✚ࡍࡿࡓࡵ㸪⤖ᬗᵓ㐀ࢆᣢࡓ࡞࠸࢔ࣔ ࣝࣇ࢓ࢫྜ㔠ࡀᚓࡽࢀࡿ㸦ᅗ1㸧㸬 ࡲࡓ㸪ᮏ◊✲࡛ࡣ㸪ࢫࣃࢵࢱ࡟౑⏝ࡍࡿࢱ࣮ࢤ ࢵࢺྜ㔠ࢆࣔࣀ࢔࣮ࢡ⁐ゎ࡟ࡼࡗ࡚స〇ࡋ࡚࠸ࡿ㸬 ࢱ࣮ࢤࢵࢺྜ㔠ࢆ௵ពࡢ⤌ᡂẚ࡛స〇ࡍࡿࡇ࡜࡛ ࠾࠾ࡼࡑᚲせ࡜ࡍࡿ⤌ᡂẚࡢ࢔ࣔࣝࣇ࢓ࢫྜ㔠ࢆ స〇ࡍࡿࡇ࡜ࡀ࡛ࡁࡿࠋᚓࡽࢀࡓ࢔ࣔࣝࣇ࢓ࢫྜ 㔠ࡣ㸪ᶵᲔⓗ◊☻࡛㖡ᇶᯈࢆ㝖ཤࡋ㸪ྛ✀≀ᛶ  ᐃ⏝࡟ࢲ࢖࢔ࣔࣥࢻ࢝ࢵࢱ࣮࡛ᡂᙧࡋࡓ㸬 2㸬2 ヨᩱホ౯࠾ࡼࡧ≀ᛶ ᐃ ヨᩱࡢᵓ㐀ࡣ㸪X ⥺ᅇᢡ ᐃ࡟ࡼࡗ࡚☜ㄆࡋࡓ㸬 ⤌ᡂࡣ㸪_{ICP Ⓨගศගศᯒἲ࠾ࡼࡧ SEM-EDS ࡞࡝} ࢆ⏝࠸࡚☜ㄆࡋࡓ㸬  ≀ᛶ ᐃࡣ㸪☢໬⋡㸪㟁Ẽ᢬ᢠ㸪ẚ⇕㸪⇕⭾ᙇ ࠾ࡼࡧ⇕㟁⬟ࡢ ᗘ౫Ꮡᛶࢆ୰ᚰ࡟⾜࠸㸪ࡑࡢ☢ Ẽⓗᛶ㉁㸪ఏᑟ≉ᛶ㸪⇕≉ᛶ࡞࡝࠿ࡽ㟁Ꮚ≧ែ࡟ ࡘ࠸࡚⪃ᐹࡋࡓ㸬 ⇕⭾ᙇࡢ ᐃ᪉ἲࡣ㸪ࢫࢺࣞ࢖ࣥࢤ࣮ࢪἲࢆ⏝ ࠸ࡓ㸬ࢫࢺࣞ࢖ࣥࢤ࣮ࢪἲ࡜ࡣ㸪㔠ᒓ⟩࡛ฟ᮶ࡓ ṍࡳࢤ࣮ࢪࡢ㟁Ẽ᢬ᢠࡢኚ໬ࡀṍࡳࡢ㔞࡟ẚ౛ࡍ ࡿࡇ࡜ࢆ฼⏝ࡋࡓṍࡳࡢ ᐃἲ࡛࠶ࡿ㸬௨๓ࡲ࡛ ࡣ㸪ᴟప ෭෾⿦⨨ࢆ⏝࠸࡚㸪_{10 K ࠿ࡽᐊ ⛬ᗘ} ࡢ ᗘ⠊ᅖ࡛↓☢ሙࡢ ᐃࢆ⾜ࡗ࡚࠸ࡓࠋࡋ࠿ࡋ㸪 ࡇࡢ᪉ἲࡢḞⅬ࡜ࡋ࡚㸪ప ᇦࡢ ᗘ୙Ᏻᐃᛶ࠿ ࡽ௚ࡢ≀ᛶ ᐃ࡟ᑐࡋ㧗࠸ ᗘ࡛ࡢ ᐃ࡟࡞ࡗ࡚ ࠸ࡓࡇ࡜࡜↓☢ሙ࡛ࡢ ᐃࡋ࠿ฟ᮶࡞࠸ࡇ࡜ࡀᣲ ࡆࡽࢀࡿ㸬ࡑࡇ࡛ᮏ◊✲࡛ࡣ㸪 ᗘ࡜☢ሙࡢࢥࣥ ࢺ࣮ࣟࣝࡀ⡆౽࡟⾜࠼ࡿᮏᏛᡤ᭷ࡢ≀⌮≉ᛶホ౯ ⿦⨨PPMS㸦Quantum Deign ♫㸧ࢆ฼⏝ࡋ࡚㸪☢ሙ ୰⇕⭾ᙇ ᐃࢩࢫࢸ࣒ࢆᵓ⠏ࡋࡓ㸬⌧ᅾ㸪_{5 ~ 300 K} ࡢ ᗘ⠊ᅖ࡛ ᗘ୍ᐃࡢୗ㸪☢ሙࢆኚ໬ࡉࡏࡓ᫬ ᅗ_{1 ࢫࣃࢵࢱἲࡢᶍᘧᅗ} ᵓ㐀౫Ꮡᕼᅵ㢮ྜ㔠ࡢ㛤Ⓨ࡜☢Ẽ⇕㔞࣭⇕ᙎᛶᮦᩱ࡬ࡢᒎ㛤

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ࡢṍࡳࡢ ᐃࡀྍ⬟࡞☢ṍ ᐃࢩࢫࢸ࣒ࡢᵓ⠏࡟ ᡂຌࡋࡓ㸬௒ᅇࡣ㸪ᐊ ࠿ࡽప ࡲ࡛ᕧ኱࡞⇕⭾ ᙇࡀほ ࡉࢀࡿ_{x = 50 ࡢヨᩱ࡟ᑐࡋ☢ṍ ᐃࢆ⾜} ࡗࡓ㸬 ᐃ ᗘࡣ㸪_{5 K, 20 K, 50 K, 80 K, 100 K,} 150 K, 200 K, 275 K, 300 K㸪☢ሙࢆ 0 ~ 60 kOe ࡲ࡛ ኚ໬ࡉࡏ࡚☢ሙ᪉ྥ࡟ᑐࡍࡿṍࡳࡢ ᐃࢆ⾜ࡗࡓ㸬 3 ⤖ᯝ࡜⪃ᐹ 3㸬1 ẚ⇕ ᅗ_{2 ࡟ x = 50 ࡢẚ⇕ࡢ ᗘ౫Ꮡᛶࢆ♧ࡍ㸬୍⯡} ࡟☢ᛶయࡢẚ⇕ࡣ㸪᱁Ꮚẚ⇕ _Cph࡜☢Ẽẚ⇕ Cmag ࡜㟁Ꮚẚ⇕_Celࡢ࿴࡛ほ ࡉࢀࡿ㸬ᐇ㦂࡛ᚓࡽࢀࡓ ࢹ࣮ࢱ࡟ᑐࡋ㸪㐺ᙜ࡞ࢹࣂ࢖ ᗘࢆỴࡵ㸪ࢹࣂ࢖ 㛵ᩘ࡟ࡼࡗ࡚Cphࡢᐤ୚ࢆぢ✚ࡶࡗࡓ㸬ࢹࣂ࢖ ᗘ ࡣ㸪_{x = 50 ࡛ 300 K ࡜ࡋࡓ㸬ࡉࡽ࡟㸪ᚓࡽࢀࡓẚ⇕} ࠿ࡽ Cphࢆᘬࡃࡇ࡜࡛☢Ẽ࠾ࡼࡧ㟁Ꮚࡢᐤ୚ࢆぢ ✚ࡶࡗࡓ㸬㧗 ഃࡢẚ⇕ࡣ㸪ぢ✚ࡶࡗࡓ_Cph࡜ᐇ㦂 ್ࡀ࡯ࡰ୍⮴ࡍࡿࡇ࡜࠿ࡽ㸪᱁Ꮚẚ⇕ࡢᐤ୚ࡢࡳ ࡛ㄝ࡛᫂ࡁࡿ࠿ࡶࡋࢀ࡞࠸㸬_{150 K ௨ୗࡢప ࡛㸪} ☢Ẽ࠾ࡼࡧ㟁Ꮚẚ⇕ࡢᐤ୚ࡀ⌧ࢀ㸪40 ~ 50 K ௜㏆ ࡟ᒣࢆᣢࡘ㸬ప ẚ⇕ࡼࡾぢ✚ࡶࡽࢀࡓ㟁Ꮚẚ⇕ ಀᩘࡣ㸪x = 50 ࡛ 95.5 mJ/molK2࡜㏻ᖖ㔠ᒓ࡟ẚ࡭ ࡚࠾ࡼࡑ_{100 ಸࡶ኱ࡁ࠸㸬} 3㸬2 ⇕⭾ᙇ ᅗ_{3 ࡟ a-Ce-Mn ྜ㔠ࡢ⥺⭾ᙇL/L ࡢ ᗘ౫Ꮡᛶ} ࢆ♧ࡍ㸬ẚ㍑ࡢࡓࡵ㸪_{Cu ࡢ⥺⭾ᙇࡢ ᗘ౫Ꮡᛶࡶ} ♧ࡍ㸬L/L ࡣ㸪ࡍ࡭࡚ࡢ⤌ᡂ࡟࠾࠸࡚ Cu ࡜ẚ㍑ ࡋ࡚኱ࡁ࠸ ᗘ౫Ꮡࢆ♧ࡍ㸬_{Ce ప⃰ᗘഃ࡛㏻ᖖ㔠} ᒓྠᵝ࡟ ᗘࡢῶᑡ࡜࡜ࡶ࡟ୗ࡟ฝࡢ ᗘ౫Ꮡࢆ ♧ࡍ㸬_{Ce ⃰ᗘ 50 at%௨ୖ࡛ࡣ㸪100 K ௜㏆ࡲ࡛⥺} ᙧⓗ࡞ῶᑡࢆ♧ࡋ㸪ࡑࡢᚋୖ࡟ฝࡢ ᗘ౫Ꮡࢆ♧ ࡍ㸬ᅗ4 ࡟ a-Ce-Mn ྜ㔠ࡢ⇕⭾ᙇಀᩘࡢ ᗘ౫Ꮡ ᛶࢆ♧ࡍ㸬ࡣ㸪_{Ce ⃰ᗘ 50 at%௨ୗࡢ㧗 ഃ࡛㏻} ᖖ㔠ᒓ࡟ẚ࡭_{2㹼3 ಸࡶࡢ್ࢆ♧ࡍ㸬ࡲࡓ㸪50 at%} ௨ୖ࡛ࡣ㸪ᖜᗈ࠸ ᗘ㡿ᇦ࡛ᕧ኱࡞್ࢆ♧ࡍ㸬₁₀₀ K ௨ୗࡢప ഃ࡛ࡣ㸪 ᗘࡢῶᑡ࡜࡜ࡶ࡟኱ࡁ࡞ ቑ኱ࢆ♧ࡋ㸪ࡑࡢᚋࣆ࣮ࢡࢆᣢࡗ࡚኱ࡁࡃῶᑡࡍ ࡿ㸬ప ࡢࡢቑ኱ࡣ㸪☢Ẽẚ⇕ࡢቑ኱࡜࠾࠾ࡼࡑ ୍⮴ࡋ࡚࠸ࡿ㸬ࡇࡢቑ኱ࡣ㸪a-(Ce,Y)-Mn ྜ㔠ࡢ◊ ✲(5)࠿ࡽ㸪㏆⸨ຠᯝ࡟ࡼࡿࡶࡢ࡜⪃࠼ࡽࢀ࡚࠸ࡿ㸬 ᅗ5 ࡟ a-Ce-Mn ྜ㔠ࡢ☢ṍࡢ☢ሙ౫Ꮡᛶࢆ♧ࡍ㸬 ࡍ࡭࡚ࡢ ᗘ࡟࠾࠸࡚㸪㈇ࡢ☢ṍࡀほ ࡉࢀࡓ㸬 ࡇࢀࡣ☢ሙ࡟ࡼࡗ࡚⇕⭾ᙇࡀᢚไࡉࢀࡓࡇ࡜ࢆ♧ ࡋ࡚࠸ࡿ㸬ࡲࡓ㸪㧗 ࣭ప☢ሙ࡛ࡣ㸪☢ሙ࡟࡯࡜ ࢇ࡝౫Ꮡࡋ࡞࠸ࡀ㸪ప ࣭㧗☢ሙ࡯࡝኱ࡁ࡞☢ሙ ౫Ꮡᛶࡀほ ࡉࢀࡓ㸬ᅗ_{6 ࡟ a-Ce-Mn ྜ㔠ࡢ☢ṍ} ࡢ ᗘ౫Ꮡᛶࢆ♧ࡍ㸬ప☢ሙഃ࡛ࡣ㸪࡯࡜ࢇ࡝  ᗘ࡟౫Ꮡࡋ࡞࠸ࡢ࡟ᑐࡋ㸪_{30 kOe ௨ୖࡢ☢ሙ࡛㸪} 100 K ௨ୗࡢప ࡛ ᗘࡢῶᑡ࡜࡜ࡶ࡟኱ࡁࡃῶ ᅗ_{2 x = 50 ࡢẚ⇕ࡢ ᗘ౫Ꮡᛶ} ᅗ_{3 a-Ce-Mn ྜ㔠ࡢ⥺⭾ᙇL/L ࡢ}  ᗘ౫Ꮡᛶ ᅗ4 a-Ce-Mn ྜ㔠ࡢ⇕⭾ᙇಀᩘࡢ  ᗘ౫Ꮡᛶ ᵓ㐀౫Ꮡᕼᅵ㢮ྜ㔠ࡢ㛤Ⓨ࡜☢Ẽ⇕㔞࣭⇕ᙎᛶᮦᩱ࡬ࡢᒎ㛤

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ࡢṍࡳࡢ ᐃࡀྍ⬟࡞☢ṍ ᐃࢩࢫࢸ࣒ࡢᵓ⠏࡟ ᡂຌࡋࡓ㸬௒ᅇࡣ㸪ᐊ ࠿ࡽప ࡲ࡛ᕧ኱࡞⇕⭾ ᙇࡀほ ࡉࢀࡿx = 50 ࡢヨᩱ࡟ᑐࡋ☢ṍ ᐃࢆ⾜ ࡗࡓ㸬 ᐃ ᗘࡣ㸪_{5 K, 20 K, 50 K, 80 K, 100 K,} 150 K, 200 K, 275 K, 300 K㸪☢ሙࢆ 0 ~ 60 kOe ࡲ࡛ ኚ໬ࡉࡏ࡚☢ሙ᪉ྥ࡟ᑐࡍࡿṍࡳࡢ ᐃࢆ⾜ࡗࡓ㸬 3 ⤖ᯝ࡜⪃ᐹ 3㸬1 ẚ⇕ ᅗ_{2 ࡟ x = 50 ࡢẚ⇕ࡢ ᗘ౫Ꮡᛶࢆ♧ࡍ㸬୍⯡} ࡟☢ᛶయࡢẚ⇕ࡣ㸪᱁Ꮚẚ⇕ _Cph࡜☢Ẽẚ⇕ _Cmag ࡜㟁Ꮚẚ⇕Celࡢ࿴࡛ほ ࡉࢀࡿ㸬ᐇ㦂࡛ᚓࡽࢀࡓ ࢹ࣮ࢱ࡟ᑐࡋ㸪㐺ᙜ࡞ࢹࣂ࢖ ᗘࢆỴࡵ㸪ࢹࣂ࢖ 㛵ᩘ࡟ࡼࡗ࡚Cphࡢᐤ୚ࢆぢ✚ࡶࡗࡓ㸬ࢹࣂ࢖ ᗘ ࡣ㸪_{x = 50 ࡛ 300 K ࡜ࡋࡓ㸬ࡉࡽ࡟㸪ᚓࡽࢀࡓẚ⇕} ࠿ࡽ Cphࢆᘬࡃࡇ࡜࡛☢Ẽ࠾ࡼࡧ㟁Ꮚࡢᐤ୚ࢆぢ ✚ࡶࡗࡓ㸬㧗 ഃࡢẚ⇕ࡣ㸪ぢ✚ࡶࡗࡓ_Cph࡜ᐇ㦂 ್ࡀ࡯ࡰ୍⮴ࡍࡿࡇ࡜࠿ࡽ㸪᱁Ꮚẚ⇕ࡢᐤ୚ࡢࡳ ࡛ㄝ࡛᫂ࡁࡿ࠿ࡶࡋࢀ࡞࠸㸬_{150 K ௨ୗࡢప ࡛㸪} ☢Ẽ࠾ࡼࡧ㟁Ꮚẚ⇕ࡢᐤ୚ࡀ⌧ࢀ㸪_{40 ~ 50 K ௜㏆} ࡟ᒣࢆᣢࡘ㸬ప ẚ⇕ࡼࡾぢ✚ࡶࡽࢀࡓ㟁Ꮚẚ⇕ ಀᩘࡣ㸪x = 50 ࡛ 95.5 mJ/molK2_{࡜㏻ᖖ㔠ᒓ࡟ẚ࡭} ࡚࠾ࡼࡑ_{100 ಸࡶ኱ࡁ࠸㸬} 3㸬2 ⇕⭾ᙇ ᅗ3 ࡟ a-Ce-Mn ྜ㔠ࡢ⥺⭾ᙇL/L ࡢ ᗘ౫Ꮡᛶ ࢆ♧ࡍ㸬ẚ㍑ࡢࡓࡵ㸪_{Cu ࡢ⥺⭾ᙇࡢ ᗘ౫Ꮡᛶࡶ} ♧ࡍ㸬L/L ࡣ㸪ࡍ࡭࡚ࡢ⤌ᡂ࡟࠾࠸࡚ Cu ࡜ẚ㍑ ࡋ࡚኱ࡁ࠸ ᗘ౫Ꮡࢆ♧ࡍ㸬Ce ప⃰ᗘഃ࡛㏻ᖖ㔠 ᒓྠᵝ࡟ ᗘࡢῶᑡ࡜࡜ࡶ࡟ୗ࡟ฝࡢ ᗘ౫Ꮡࢆ ♧ࡍ㸬_{Ce ⃰ᗘ 50 at%௨ୖ࡛ࡣ㸪100 K ௜㏆ࡲ࡛⥺} ᙧⓗ࡞ῶᑡࢆ♧ࡋ㸪ࡑࡢᚋୖ࡟ฝࡢ ᗘ౫Ꮡࢆ♧ ࡍ㸬ᅗ_{4 ࡟ a-Ce-Mn ྜ㔠ࡢ⇕⭾ᙇಀᩘ}ࡢ ᗘ౫Ꮡ ᛶࢆ♧ࡍ㸬ࡣ㸪_{Ce ⃰ᗘ 50 at%௨ୗࡢ㧗 ഃ࡛㏻} ᖖ㔠ᒓ࡟ẚ࡭_{2㹼3 ಸࡶࡢ್ࢆ♧ࡍ㸬ࡲࡓ㸪50 at%} ௨ୖ࡛ࡣ㸪ᖜᗈ࠸ ᗘ㡿ᇦ࡛ᕧ኱࡞್ࢆ♧ࡍ㸬100 K ௨ୗࡢప ഃ࡛ࡣ㸪 ᗘࡢῶᑡ࡜࡜ࡶ࡟኱ࡁ࡞ ቑ኱ࢆ♧ࡋ㸪ࡑࡢᚋࣆ࣮ࢡࢆᣢࡗ࡚኱ࡁࡃῶᑡࡍ ࡿ㸬ప ࡢࡢቑ኱ࡣ㸪☢Ẽẚ⇕ࡢቑ኱࡜࠾࠾ࡼࡑ ୍⮴ࡋ࡚࠸ࡿ㸬ࡇࡢቑ኱ࡣ㸪a-(Ce,Y)-Mn ྜ㔠ࡢ◊ ✲(5)_{࠿ࡽ㸪㏆⸨ຠᯝ࡟ࡼࡿࡶࡢ࡜⪃࠼ࡽࢀ࡚࠸ࡿ㸬} ᅗ_{5 ࡟ a-Ce-Mn ྜ㔠ࡢ☢ṍࡢ☢ሙ౫Ꮡᛶࢆ♧ࡍ㸬} ࡍ࡭࡚ࡢ ᗘ࡟࠾࠸࡚㸪㈇ࡢ☢ṍࡀほ ࡉࢀࡓ㸬 ࡇࢀࡣ☢ሙ࡟ࡼࡗ࡚⇕⭾ᙇࡀᢚไࡉࢀࡓࡇ࡜ࢆ♧ ࡋ࡚࠸ࡿ㸬ࡲࡓ㸪㧗 ࣭ప☢ሙ࡛ࡣ㸪☢ሙ࡟࡯࡜ ࢇ࡝౫Ꮡࡋ࡞࠸ࡀ㸪ప ࣭㧗☢ሙ࡯࡝኱ࡁ࡞☢ሙ ౫Ꮡᛶࡀほ ࡉࢀࡓ㸬ᅗ_{6 ࡟ a-Ce-Mn ྜ㔠ࡢ☢ṍ} ࡢ ᗘ౫Ꮡᛶࢆ♧ࡍ㸬ప☢ሙഃ࡛ࡣ㸪࡯࡜ࢇ࡝  ᗘ࡟౫Ꮡࡋ࡞࠸ࡢ࡟ᑐࡋ㸪_{30 kOe ௨ୖࡢ☢ሙ࡛㸪} 100 K ௨ୗࡢప ࡛ ᗘࡢῶᑡ࡜࡜ࡶ࡟኱ࡁࡃῶ ᅗ_{2 x = 50 ࡢẚ⇕ࡢ ᗘ౫Ꮡᛶ} ᅗ_{3 a-Ce-Mn ྜ㔠ࡢ⥺⭾ᙇL/L ࡢ}  ᗘ౫Ꮡᛶ ᅗ_{4 a-Ce-Mn ྜ㔠ࡢ⇕⭾ᙇಀᩘ}ࡢ  ᗘ౫Ꮡᛶ

－　40　－ 㞵ᾏ ᭷భ㸪ሷᑼ Ὀᗈ㸪㕥ᮌ ᣅஓ㸪▼ཎ ᆂ㸪ᮧᒣ ⱱᖾ

- 40 -

ᑡࡍࡿ㸬ࡇࢀࡣ㸪㏆⸨ຠᯝ࡟ࡼࡿ⇕⭾ᙇࡢቑ኱ࡀ ☢ሙ࡟ࡼࡗ࡚ᢚไࡉࢀࡓࡇ࡜ࢆ♧၀ࡍࡿ㸬ᚑࡗ࡚㸪 a-Ce-Mn ྜ㔠ࡢప ࡢ⇕⭾ᙇࡣ㸪☢ሙ࡟ࡼࡗ࡚ఏ ᑟ㟁Ꮚ࡜4f 㟁Ꮚࡢΰᡂࢆไᚚࡋ⇕⭾ᙇࢆࢥࣥࢺࣟ ࣮࡛ࣝࡁࡿࡇ࡜ࡀࢃ࠿ࡗࡓ㸬ࡋ࠿ࡋ㸪㧗 ഃࡢᕧ ኱࡞⇕⭾ᙇಀᩘࡀኚ໬ࡋࡓ࠿࡝࠺࠿ࡣ௒ᅇࡢ ᐃ ἲ࠾ࡼࡧ᮲௳࡛ࡣࡲࡔࢃ࠿ࡽ࡞࠸ࠋ 4 ࡲ࡜ࡵ࡜௒ᚋࡢᒎᮃ ᮏ◊✲ࡣ㸪_{Ce ࢆ୰ᚰ࡜ࡋࡓ࢔ࣔࣝࣇ࢓ࢫྜ㔠࡟} ࠾ࡅࡿᙉ┦㛵㟁Ꮚ≀ᛶࢆά࠿ࡋࡓḟୡ௦ࡢ㧗ᶵ⬟ ᮦᩱࡢ㛤Ⓨࢆ┠ᣦࡋ࡚㸪࢔ࣔࣝࣇ࢓ࢫᵓ㐀ࡺ࠼࡟ Ꮡᅾྍ⬟࡞a-CexMn100-xྜ㔠ࡢᇶ♏≀ᛶ ᐃ࡜␗ᖖ ࡞⇕⭾ᙇࡢゎ᫂ࢆ⾜࠺ࡓࡵ㸪☢ṍࡢ ᐃࢆ⾜ࡗࡓ㸬 ⤌ᡂࡀᣕᢠࡍࡿx = 50 ࡛ࡣ㸪ᙉ┦㛵㟁Ꮚ≧ែ㸦㏆ ⸨ຠᯝ㸧࡟ࡼࡗ࡚⇕⭾ᙇಀᩘࡀ_{100 K ௨ୗࡢప} ࡛ ᗘࡢῶᑡ࡜࡜ࡶ࡟ቑ኱ࡍࡿࡇ࡜ࡀࢃ࠿ࡗࡓ㸬 ࡲࡓ㸪☢ሙ࡟ࡼࡗ࡚㏆⸨ຠᯝࡀᢚไࡉࢀ㸪㈇ࡢ☢ ṍࡀほ ࡉࢀࡓ㸬ᚑࡗ࡚㸪ప ࡛ࡢ⇕⭾ᙇࡢቑ኱ ࡣ☢ሙ࡟ࡼࡗ࡚ไᚚ࡛ࡁࡿࡇ࡜ࡀࢃ࠿ࡗࡓ㸬  ௒ᚋࡣ㸪☢ṍࡔࡅ࡛࡞ࡃ⇕⭾ᙇࡢ☢ሙ୰ࡢ ᗘ ౫Ꮡᛶࢆ ᐃࡍࡿࢩࢫࢸ࣒ࢆᵓ⠏ࡋ㸪a-Ce-Mn ྜ 㔠ࡢ⇕⭾ᙇࡢ☢ሙࡢຠᯝࢆࡉࡽ࡟᫂ࡽ࠿࡟ࡍࡿ㸬 ࡲࡓ㸪㏆⸨ຠᯝࡢᢚไ࡟ࡼࡗ࡚⇕⭾ᙇࡀࢥࣥࢺࣟ ࣮ࣝࡉࢀࡿࡇ࡜࠿ࡽ㸪_{a-Ce-Mn ྜ㔠࡟ᑐࡋඖ⣲⨨} ᥮࡟ࡼࡗ࡚㟁Ꮚ≧ែࢆኚ໬ࡉࡏ㸪⇕⭾ᙇࡢࢥࣥࢺ ࣮ࣟࣝࢆヨࡳࡿ㸬ࡉࡽ࡟㸪ᮏ◊✲࡟࠾ࡅࡿヨᩱస 〇ἲࢆά࠿ࡋ㸪⤌ᡂࢆഴᩳ໬ࡉࡏࡓヨᩱࢆస〇ࡋ㸪  ᗘ࣭☢ሙࡢࢥࣥࢺ࣮࡛ࣟࣝ㥑ືࡍࡿ࢔ࢡࢳ࢚ࣗ ࣮ࢱ࣮⣲Ꮚࡸ⇕⭾ᙇࡢ㐪࠺ᮦᩱࡢ᥋ྜ࡞࡝࡟฼⏝ ࡛ࡁࡿᮦᩱࡢ㛤Ⓨࢆ┠ᣦࡍ㸬 ㅰ㎡ ᮏ◊✲ࡣ㸪_{JST ◊✲ᡂᯝᒎ㛤஦ᴗ ◊✲ᡂᯝ᭱㐺} ᒎ㛤ᨭ᥼ࣉࣟࢢ࣒ࣛࣇ࢕࣮ࢪࣅࣜࢸ࢕ࢫࢱࢹ࢕ ࠙㹄㹑ࠚࢫࢸ࣮ࢪ㸦_{A-STEP㸧㸪᥈⣴ࢱ࢖ࣉ㸦␒ྕ} AS232Z02108C㸧ࠕᵓ㐀ࡢ஘ࢀࡀ⏕ࡳฟࡍ㧗ᶵ⬟ᕼ ᅵ㢮ᮦᩱࡢ㛤Ⓨࠖ㸦_{2011㹼2012㸧࠾ࡼࡧ㸪ᖹᡂ 22} ᖺᗘᐊ⹒ᕤᴗ኱Ꮫ㸰㸯ୡ⣖⛉Ꮫ◊✲㈝ࠕᵓ㐀୙つ ๎ᙉ┦㛵ᕼᅵ㢮ྜ㔠ࡢ␗ᖖ⇕ᙎᛶ࡟㛵ࡍࡿ◊✲ࠖ ࡢຓᡂࢆཷࡅ࡚⾜ࢃࢀࡓࠋ ཧ⪃ᩥ⊩

(1) S. Kikegawa, T. Matsumura, S. Murayama, H. Takano, and Y. Obi, Magnetic properties of amorphous Mn100−xCex alloys, Physica B, 329-333 (2003)

p1074-1076.

(2) S. Kikegawa, Y. Amakai, K. Asano, S. Murayama, and H. Takano, Y. Obi, Specific heat of amorphous Mn100-xCex

alloys, J. Magn. & Magn. Mater. 272-276 (2004) p72-74.

(3) Y. Amakai, S. Murayama, Y. Obi, H. Takano, and K. Takanashi, Evidence of a heavy fermion state in the disordered Ce-alloys system without translation symmetry, Phys. Rev. B, 79 (2009) 241526 (6 pages). (4) Y. Amakai, S. Murayama, Y. Obi, H. Takano, N.

Momono, and K. Takanashi, Magnetic properties of structure-disordered heavy fermion Ce-Mn alloys, J. Phys.: Conf. Ser., 200 (2010) 012006 (4 pages).

(5) Y. Amakai, S. Murayama, Y. Obi, H. Takano, N. Momono, and K. Takanashi, Thermal expansion of structure-disordered heavy-fermion Ce alloys, J. Phys. Soc. Jpn., 80 (2011) SA057 (3 pages).

ᅗ6 x = 50 ࡢ☢ṍࡢ ᗘ౫Ꮡᛶ ᅗ_{5 x = 50 ࡢ☢ṍࡢ☢ሙ౫Ꮡᛶ} 㞵ᾏ ᭷భ㸪ሷᑼ Ὀᗈ㸪㕥ᮌ ᣅஓ㸪▼ཎ ᆂ㸪ᮧᒣ ⱱᖾ

- 40 -

ᑡࡍࡿ㸬ࡇࢀࡣ㸪㏆⸨ຠᯝ࡟ࡼࡿ⇕⭾ᙇࡢቑ኱ࡀ ☢ሙ࡟ࡼࡗ࡚ᢚไࡉࢀࡓࡇ࡜ࢆ♧၀ࡍࡿ㸬ᚑࡗ࡚㸪 a-Ce-Mn ྜ㔠ࡢప ࡢ⇕⭾ᙇࡣ㸪☢ሙ࡟ࡼࡗ࡚ఏ ᑟ㟁Ꮚ࡜_{4f 㟁Ꮚࡢΰᡂࢆไᚚࡋ⇕⭾ᙇࢆࢥࣥࢺࣟ} ࣮࡛ࣝࡁࡿࡇ࡜ࡀࢃ࠿ࡗࡓ㸬ࡋ࠿ࡋ㸪㧗 ഃࡢᕧ ኱࡞⇕⭾ᙇಀᩘࡀኚ໬ࡋࡓ࠿࡝࠺࠿ࡣ௒ᅇࡢ ᐃ ἲ࠾ࡼࡧ᮲௳࡛ࡣࡲࡔࢃ࠿ࡽ࡞࠸ࠋ 4 ࡲ࡜ࡵ࡜௒ᚋࡢᒎᮃ ᮏ◊✲ࡣ㸪_{Ce ࢆ୰ᚰ࡜ࡋࡓ࢔ࣔࣝࣇ࢓ࢫྜ㔠࡟} ࠾ࡅࡿᙉ┦㛵㟁Ꮚ≀ᛶࢆά࠿ࡋࡓḟୡ௦ࡢ㧗ᶵ⬟ ᮦᩱࡢ㛤Ⓨࢆ┠ᣦࡋ࡚㸪࢔ࣔࣝࣇ࢓ࢫᵓ㐀ࡺ࠼࡟ Ꮡᅾྍ⬟࡞a-CexMn100-xྜ㔠ࡢᇶ♏≀ᛶ ᐃ࡜␗ᖖ ࡞⇕⭾ᙇࡢゎ᫂ࢆ⾜࠺ࡓࡵ㸪☢ṍࡢ ᐃࢆ⾜ࡗࡓ㸬 ⤌ᡂࡀᣕᢠࡍࡿx = 50 ࡛ࡣ㸪ᙉ┦㛵㟁Ꮚ≧ែ㸦㏆ ⸨ຠᯝ㸧࡟ࡼࡗ࡚⇕⭾ᙇಀᩘࡀ_{100 K ௨ୗࡢప} ࡛ ᗘࡢῶᑡ࡜࡜ࡶ࡟ቑ኱ࡍࡿࡇ࡜ࡀࢃ࠿ࡗࡓ㸬 ࡲࡓ㸪☢ሙ࡟ࡼࡗ࡚㏆⸨ຠᯝࡀᢚไࡉࢀ㸪㈇ࡢ☢ ṍࡀほ ࡉࢀࡓ㸬ᚑࡗ࡚㸪ప ࡛ࡢ⇕⭾ᙇࡢቑ኱ ࡣ☢ሙ࡟ࡼࡗ࡚ไᚚ࡛ࡁࡿࡇ࡜ࡀࢃ࠿ࡗࡓ㸬  ௒ᚋࡣ㸪☢ṍࡔࡅ࡛࡞ࡃ⇕⭾ᙇࡢ☢ሙ୰ࡢ ᗘ ౫Ꮡᛶࢆ ᐃࡍࡿࢩࢫࢸ࣒ࢆᵓ⠏ࡋ㸪_{a-Ce-Mn ྜ} 㔠ࡢ⇕⭾ᙇࡢ☢ሙࡢຠᯝࢆࡉࡽ࡟᫂ࡽ࠿࡟ࡍࡿ㸬 ࡲࡓ㸪㏆⸨ຠᯝࡢᢚไ࡟ࡼࡗ࡚⇕⭾ᙇࡀࢥࣥࢺࣟ ࣮ࣝࡉࢀࡿࡇ࡜࠿ࡽ㸪a-Ce-Mn ྜ㔠࡟ᑐࡋඖ⣲⨨ ᥮࡟ࡼࡗ࡚㟁Ꮚ≧ែࢆኚ໬ࡉࡏ㸪⇕⭾ᙇࡢࢥࣥࢺ ࣮ࣟࣝࢆヨࡳࡿ㸬ࡉࡽ࡟㸪ᮏ◊✲࡟࠾ࡅࡿヨᩱస 〇ἲࢆά࠿ࡋ㸪⤌ᡂࢆഴᩳ໬ࡉࡏࡓヨᩱࢆస〇ࡋ㸪  ᗘ࣭☢ሙࡢࢥࣥࢺ࣮࡛ࣟࣝ㥑ືࡍࡿ࢔ࢡࢳ࢚ࣗ ࣮ࢱ࣮⣲Ꮚࡸ⇕⭾ᙇࡢ㐪࠺ᮦᩱࡢ᥋ྜ࡞࡝࡟฼⏝ ࡛ࡁࡿᮦᩱࡢ㛤Ⓨࢆ┠ᣦࡍ㸬 ㅰ㎡ ᮏ◊✲ࡣ㸪_{JST ◊✲ᡂᯝᒎ㛤஦ᴗ ◊✲ᡂᯝ᭱㐺} ᒎ㛤ᨭ᥼ࣉࣟࢢ࣒ࣛࣇ࢕࣮ࢪࣅࣜࢸ࢕ࢫࢱࢹ࢕ ࠙㹄㹑ࠚࢫࢸ࣮ࢪ㸦_{A-STEP㸧㸪᥈⣴ࢱ࢖ࣉ㸦␒ྕ} AS232Z02108C㸧ࠕᵓ㐀ࡢ஘ࢀࡀ⏕ࡳฟࡍ㧗ᶵ⬟ᕼ ᅵ㢮ᮦᩱࡢ㛤Ⓨࠖ㸦_{2011㹼2012㸧࠾ࡼࡧ㸪ᖹᡂ 22} ᖺᗘᐊ⹒ᕤᴗ኱Ꮫ㸰㸯ୡ⣖⛉Ꮫ◊✲㈝ࠕᵓ㐀୙つ ๎ᙉ┦㛵ᕼᅵ㢮ྜ㔠ࡢ␗ᖖ⇕ᙎᛶ࡟㛵ࡍࡿ◊✲ࠖ ࡢຓᡂࢆཷࡅ࡚⾜ࢃࢀࡓࠋ ཧ⪃ᩥ⊩

(1) S. Kikegawa, T. Matsumura, S. Murayama, H. Takano, and Y. Obi, Magnetic properties of amorphous Mn100−xCex alloys, Physica B, 329-333 (2003)

p1074-1076.

(2) S. Kikegawa, Y. Amakai, K. Asano, S. Murayama, and H. Takano, Y. Obi, Specific heat of amorphous Mn100-xCex

alloys, J. Magn. & Magn. Mater. 272-276 (2004) p72-74.

(3) Y. Amakai, S. Murayama, Y. Obi, H. Takano, and K. Takanashi, Evidence of a heavy fermion state in the disordered Ce-alloys system without translation symmetry, Phys. Rev. B, 79 (2009) 241526 (6 pages). (4) Y. Amakai, S. Murayama, Y. Obi, H. Takano, N.

Momono, and K. Takanashi, Magnetic properties of structure-disordered heavy fermion Ce-Mn alloys, J. Phys.: Conf. Ser., 200 (2010) 012006 (4 pages).

(5) Y. Amakai, S. Murayama, Y. Obi, H. Takano, N. Momono, and K. Takanashi, Thermal expansion of structure-disordered heavy-fermion Ce alloys, J. Phys. Soc. Jpn., 80 (2011) SA057 (3 pages).

ᅗ_{6 x = 50 ࡢ☢ṍࡢ ᗘ౫Ꮡᛶ} ᅗ5 x = 50 ࡢ☢ṍࡢ☢ሙ౫Ꮡᛶ ᐊᕤ኱⣖せ➨_{63 ྕ㸦2013㸧 41㹼44}

- 41 -

㗪㕲࣭࢔࣑ࣝࢽ࣒࢘⁐‮ฎ⌮࡟ཬࡰࡍࣞ࢔࢔࣮ࢫࡢຠᯝ



㛗⯪

ᗣ⿱

*1*2

_㸪⏣‮

_ၿ❶

*1*2

_㸪᱈㔝

_ṇ

*1*2

Effect of Rear Earth Element on Melt Process for Cast Iron and Aluminum

Yasuhiro OSAFUNE

*1*2

_{, Yoshinori TAYU}

*1*2

_{, and Tadashi MOMONO}

*1*2

㸦ཎ✏ཷ௜᪥ ᖹᡂ

_{25 ᖺ 9 ᭶ 30 ᪥ ㄽᩥཷ⌮᪥ ᖹᡂ 26 ᖺ 1 ᭶ 24 ᪥㸧}

Abstract

In the manufacture of cast product, various melt processing is carried out between melting of iron and pouring molten metal into a mold. We have been researching on casting technology for high-quality for cast aluminum and cast iron. Information in this report is as follows : ձEffect of rear earth element on molten metal treatment of cast iron. ղEffect of CE value and chemical composition on chilling of tin wall cast iron. ճHolding of lecture on cast iron and rear earth element. մGrain refinement of Al-Si alloy by electromagnetic stirring.

Keywords : Cast iron, Aluminum, Rear earth element, Casting technology, Inoculation, Thin wall casting, Electromagnetic stirring

1ࡣࡌࡵ࡟ 㗪㐀〇ရࡢ〇㐀࡟࠾࠸࡚㸪⁐ゎࡉࢀࡓ⁐‮ࡣ㗪 ᆺ࡟ὀࡀࢀࡿࡲ࡛࡟ᵝࠎ࡞⁐‮ฎ⌮ࡀ⾜ࢃࢀ࡚࠸ ࡿ㸬ᕼᅵ㢮ࣉࣟࢪ࢙ࢡࢺࡢࢱࢫࢡ◊✲࡛㗪㕲㗪≀ ࡜࢔࣑ࣝࢽ࣒࢘㗪≀ࢆᑐ㇟࡜ࡋ࡚㧗ရ఩໬ࡢࡓࡵ ࡢ⁐‮ฎ⌮ࢆ୰ᚰ࡜ࡋࡓ㗪㐀ᢏ⾡࡟㛵ࡍࡿ◊✲ࢆ ⾜ࡗ࡚࠸ࡿ㸬 ᖺᗘࡢ◊✲ཬࡧάືෆᐜ࡟ࡘ࠸ ࡚⤂௓ࡍࡿ㸬  2 ◊✲ཬࡧάືෆᐜ  㗪㕲ࡢ⁐‮ฎ⌮࡟ཬࡰࡍࣞ࢔࢔࣮ࢫࡢຠᯝ 㖧㕲㗪≀ࡢ⏕⏘㔞ࡣ⣙  ୓ࢺࣥ ᖺ࡛㸪 ࡑࡢ 㸣ࡣ⮬ື㌴ࢆ୰ᚰ࡜ࡍࡿ㍺㏦ᶵᲔ࡛฼⏝ࡉ ࢀ࡚࠸ࡿ_{㸬㖧㕲㗪≀ࡢ㗪㐀࡟࠾࠸࡚ࣞ࢔࢔࣮ࢫඖ} ⣲㸦5(㸧ࡀῧຍࡉࢀࡿࡇ࡜ࡀ࠶ࡿࡀ㸪ࡑࡢ⏝㏵࡜ ࡋ࡚ࡣᘬࡅᕢ࡞࡝ࡢ㗪㐀Ḟ㝗ࡢ㜵Ṇ㸪ⷧ⫗㒊ศࡢ ⬤໬ࡢᢚไࡀ࠶ࡆࡽࢀࡿ㸬 ᖺࡢ୰ᅜ⁺⯪ࡢᑤ 㛶ㅖᓥ㡿ᾏ౵≢ࢆⓎ➃࡜ࡋࡓࣞ࢔࢔࣮ࢫࣃࢽࢵࢡ  ࡀⓎ⏕ࡋ㸪᪥ᮏᅜෆ࡛ࡣࣞ࢔࢔࣮ࢫࢆ౑⏝ࡋ࡞࠸ 㗪㐀ᢏ⾡ࡢ◊✲ࡀᛴົ࡜࡞ࡗࡓ㸬ࡋ࠿ࡋ㸪⌧ᅾ࡛ ࡣ୰ᅜ௨እ࠿ࡽࡢ㍺ධࡶᣑ኱ࡋ㸪㗪㐀࡛฼⏝ࡉࢀ ࡚࠸ࡿ &H ࡸ /D ࡞࡝ࡢ㍍ᕼᅵ㢮ඖ⣲ࡢ౪⤥ࡣᏳᐃ ࡋ࡚࠸ࡿ㸬ࡲࡓ㸪ࡇࢀࡽ㍍ᕼᅵ㢮ඖ⣲ࡣᕼᑡᛶࡢ 㧗࠸ 1G ࡸ 6P ࡞࡝ࡢ㔜ᕼᅵ㢮ඖ⣲ࡢ⢭〇᫬ࡢ๪⏘ ≀࡛࠶ࡿ㸬ࡑࡢࡓࡵ㸪㍍ᕼᅵ㢮ඖ⣲ࡢ౪⤥㔞ࡣ㔜 ᕼᅵ㢮ඖ⣲࡟ẚ࡭ࡿ࡜ከࡃ㸪ࡑࡢຠᯝⓗ࡞฼⏝᪉ ἲࡀồࡵࡽࢀ࡚࠸ࡿ㸬ᮏ◊✲࡛ࡣ 5( ࡢ✚ᴟⓗ࡞ά ⏝࡜ 5( ࣞࢫ໬ᢏ⾡ࡢ୧㠃ࡢ◊✲ࢆ⾜ࡗ࡚࠸ࡿ㸬ࡲ ࡓ㸪Ẹ㛫௻ᴗ࡜ࡢ㐃ᦠࡸㅮ₇఍ࡢᐇ᪋࡟ࡼࡗ࡚◊ ✲ᡂᯝࡢ♫఍㑏ඖ࡟ດࡵ࡚࠸ࡿࡇ࡜ࢆ┠ⓗ࡜ࡋࡓ㸬   ⌫≧㯮㖄㗪㕲ࡢ⁐‮ฎ⌮࡟࠾ࡅࡿ 5( ࡢຠ ᯝ࡜⁐‮ᛶ≧ࡢุᐃᢏ⾡ࡢ㛤Ⓨ ⌫≧㯮㖄㗪㕲࡟࠾ࡅࡿ⁐‮ฎ⌮᫬ࡢ 5( ῧຍࡣඹ ᬗจᅛ᫬ࡢᬗฟ㯮㖄⢏ࡢቑຍࢆಁ㐍ࡋ㸪ᘬࡅᕢࡢ Ⓨ⏕ࡸⷧ⫗㒊ࡢ⬤໬ࢆᢚไࡍࡿ┠ⓗ࡛⾜ࢃࢀ࡚࠸ ࡿ㸬୍⯡ⓗ࡟ )H0J&D5( ྜ㔠ࡀ౑⏝ࡉࢀ࡚࠸ࡿ㸬 ࡑࡢྜ㔠ࡢ 5( ࡟ࡣ࣑ࢵࢩ࣓ࣗࢱࣝ㸦&H ࡜ /D ࡀ୺ ᡂศ㸧ࡀ⁐‮඲㔞࡟ᑐࡋ࡚ 㹼PDVV㸣ῧຍ ࡉࢀ࡚࠸ࡿ㸬ᮏ◊✲࡛ࡣ &H ཬࡧ /D ༢యࡢຠᯝࢆ *1 ᐊ⹒ᕤᴗ኱Ꮫ ࡶࡢ๰㐀⣔㡿ᇦ *2 ᐊ⹒ᕤᴗ኱Ꮫ ⎔ቃㄪ࿴ᮦᩱᕤᏛ◊✲ࢭࣥࢱ࣮