䊉䊷䊃㩷

䊉䊷䊃㩷

㊄ዻ᳓⚛ൻ‛↪੤ᵹ⏛᧤⸘䈱᭴▽䈫䈠䈱ᕈ⢻⹏ଔ㩷

㩷

⿒ਣᖗ჻ޔጟ㦮࿻␭ޔේ ᱜᙗޔ᧻ጊ᡽ᄦ ንጊᄢቇ᳓⚛ห૏૕⑼ቇ⎇ⓥ࠮ࡦ࠲࡯

ޥ

930-8555

ንጊᏒ੖⑔

3190

㪚㫆㫅㫊㫋㫉㫌㪺㫋㫀㫆㫅㩷㫆㪽㩷㪘㫃㫋㪼㫉㫅㪸㫋㫀㫅㪾㪄㪚㫌㫉㫉㪼㫅㫋㩷㪤㪸㪾㫅㪼㫋㫆㫄㪼㫋㪼㫉㩷㪽㫆㫉㩷㪤㪼㫋㪸㫃㩷㪟㫐㪻㫉㫀㪻㪼㩷 㩷 㪸㫅㪻㩷㪠㫋㫊㩷㪧㪼㫉㪽㫆㫉㫄㪸㫅㪺㪼㩷㪫㪼㫊㫋㫊㩷

㩷

Satoshi Akamaru, Keisuke Okazaki, Masanori Hara, and Masao Matsuyama Hydrogen Isotope Research Center, University of Toyama, Gofuku 3190, Toyama

930-8555, Japan

(Received November 21 , 2011; accepted March 9, 2012) Abstract

An alternating-current magnetometer was assembled to measure the magnetic susceptibility of metal hydride in hydrogen atmosphere, and its performance tests were carried out. The magnetometer was designed to be integrated into the conventional pressure-composition-temperature (PCT) measurement system without any reconstruction. Calibration of the magnetometer was performed using a paramagnetic Gd

₂

O

₃

powder, and it gave a linear relationship between the output signal and the magnetic moment of Gd

₂

O

₃

powder. The magnetic susceptibility of PdH

_x

(0

≤

x

≤

0.7) was measured simultaneously with the PCT curve. The magnetic susceptibility of Pd hydride decreased with increasing hydrogen concentration in Pd and finally reached zero at the hydrogen concentration above 0.65. The behavior of magnetic susceptibility and PCT curves quantitatively agreed with the previously reported values.

1. ✜⸒

㊄ዻ᳓⚛ൻ‛ߪ᳓⚛⾂⬿᧚ᢱߣߒߡߩᔕ↪߇ᦼᓙߐࠇߡ߅ࠅޔᄙ⒳ᄙ᭽ߥ᧚ᢱ㐿⊒෸߮

ߘߩ᳓⚛ๆ෼᡼಴․ᕈߦ㑐ߔࠆၮ␆⎇ⓥ߇⋓ࠎߦⴕࠊࠇߡ޿ࠆޕ৻ᣇߢ㊄ዻ᳓⚛ൻ‛ߩ‛

ᕈ㧔㔚⏛᳇ޔᾲޔశ‛ᕈߥߤ㧕ࠍ೑↪ߒߚᔕ↪⎇ⓥ

[1,2]

߽ⴕࠊࠇߡ޿ࠆ߇ޔ᳓⚛⾂⬿᧚ᢱ㑐 ㅪߩ⎇ⓥߣᲧセߔࠆߣዋߥ޿ޕߘߩ৻ߟߩⷐ࿃ߣߒߡޔ㊄ዻ᳓⚛ൻ‛ߩ‛ᕈߦ㑐ߔࠆၮ␆

⎇ⓥ߇ዋߥ޿ߎߣ߇⠨߃ࠄࠇࠆޕ

㊄ዻߩ⏛᳇․ᕈߪޔฎߊ߆ࠄ᭽ޘߥᎿᬺ⵾ຠߦᔕ↪ߐࠇߡ޿ࠆޕ߹ߚޔ⃻࿷ߦ߅޿ߡ߽

⏛ᕈ᧚ᢱߩᕈ⢻ะ਄ࠍ⋡ᜰߒߚ㐿⊒⎇ⓥ߇ⴕࠊࠇߡ޿ࠆޕ᧚ᢱ㐿⊒ߩⷰὐ߆ࠄ⷗ࠆߣޔ㊄ ዻ᳓⚛ൻ‛ߪ⚿᥏ߩ᭴ㅧᄌൻࠍᒁ߈⿠ߎߔߎߣ߆ࠄޔ⏛᳇․ᕈߩ೙ᓮᚗ޿ߪᣂߚߥ․ᕈߩ

⊒⃻ߦ೑↪ߢ߈ࠆߣ⠨߃ࠄࠇࠆޕߒ߆ߒޔ㊄ዻ᳓⚛ൻ‛ߪ᳓⚛ๆ෼ߦࠃࠅᄙߊ߇ᓸ☳ൻߒޔ ᄢ᳇ਛߦขࠅ಴ߔ㓙ߦ⴫㕙㉄ൻߩᓇ㗀ࠍฃߌࠆߚ߼ޔ㊄ዻ᳓⚛ൻ‛ߦኻߔࠆ⏛᳇․ᕈߩᱜ

⏕ߥ᷹ቯ߇࿎㔍ߢ޽ߞߚޕ

ߘߎߢᧄႎ๔ߢߪޔ᳓⚛ๆ෼᡼಴․ᕈߩ⹏ଔߦ↪޿ࠄࠇߡ޿ࠆޔ࿶ജ - ⚵ᚑ - ᷷ᐲ․ᕈ 㧔 PCT 㧕᷹ቯⵝ⟎߆ࠄ㊄ዻ᳓⚛ൻ‛ࠍขࠅ಴ߔߎߣߥߊޔ᳓⚛ࠟࠬ㔓࿐᳇ਛߦߡޔ᳓⚛ൻ‛

ߩ⏛᳇․ᕈࠍ᷹ቯߔࠆߚ߼ޔ PCT ᷹ቯⵝ⟎ߦኈᤃߦ⚵ߺㄟ߼ࠆ੤ᵹ⏛᧤⸘ߩ᭴▽ࠍⴕ޿ޔ ߘߩᕈ⢻⹏ଔࠍ Pd ☳ᧃࠍ↪޿ߡⴕߞߚޕ

2. ੤ᵹ⏛᧤⸘ߩේℂߣⵝ⟎ߩ᭴▽

2.1. ⶄ⚛⏛ൻ₸

ߪߓ߼ߦ੤ᵹ⏛႐ਅߢߩ⏛ൻ₸ߦߟ޿ߡ◲නߦ⺑᣿ߔࠆ [3] ޕ⏛႐ߩᣇะ߇๟ᦼ⊛ߦᄌൻ ߔࠆ੤ᵹ⏛႐ਅߦ⹜ᢱ߇޽ࠆ႐วޔ⹜ᢱߩ⏛ൻ₸ χ ^(m

³

^/kg) ߪⶄ⚛⏛ൻ₸ χ ˆ ߣߒߡએਅߩࠃ ߁ߦ⸥ㅀߐࠇࠆޕ

χ χ

χ ˆ = ′ − j ′′ ^…(1)

ߎߎߢޔj ߪ⯯ᢙන૏ࠍ⴫ߔޕ৻⥸ߦ χ′ ߪ⏛᳇ᔕ╵ߩ๟ᵄᢙଐሽᕈࠍ␜ߒޔ χ ′′ ߪ⏛ᕈ૕ౝ

ߩ౒㡆࡮✭๺⃻⽎ߦࠃࠆ⏛᳇ᔕ╵ߩㆃࠇࠍ␜ߒߡ޿ࠆޕߥ߅ޔߎߎߢߪ SI න૏♽㧔E -

B

ኻ ᔕ㧕ࠍ↪޿ߡోߡߩᑼࠍ⸥ㅀߔࠆޕ੤ᵹ⏛႐ H ˆ (Am

^-1

) ਅߢߩ⏛ൻ₸ χ ˆ ޔ⹜ᢱਛߩ⏛᧤ኒᐲ

B ˆ (Wb/m

²

) ޔ෸߮⹜ᢱߩ⾰㊂⏛ൻ M ˆ (Am

²

/kg) ߣߩ㑐ଥߪ㕒⏛႐ਅߢߩ㑐ଥߣᄌࠊࠄߕޔ

( ) ^H

B ˆ 1 ˆ ˆ

0

χ

µ +

= ޔ M ˆ = χ ˆ H ˆ ^{…(2, 3)}

ߣߥࠆޕߎߎߢޔ µ

₀

ߪ⌀ⓨਛߩㅘ⏛₸ࠍ␜ߔޕ੤ᵹ⏛႐ H ˆ _{ߩⷺᝄേᢙࠍ} ω ⁽²

π

/sec) ߣߔࠆ ߣޔ H ˆ _෸߮ B ˆ ߪએਅߩࠃ߁ߦ⸥ㅀߐࠇࠆޕ

t H

H ˆ exp ω

=

0

^…(4)

( ^{ω − δ} )

= B t

B ˆ exp

0

…(5)

H

0

෸߮ B

₀

ߪߘࠇߙࠇߩᝄ᏷ߩᄢ߈ߐߢ޽ࠅޔ t ^(sec) ߪᤨ㑆ߢ޽ࠆޕ B ˆ _{ߦ౉ߞߡ޿ࠆ} δ ߪޔ

H

0

߆ࠄߩ૏⋧ߩㆃࠇࠍ␜ߔޕ਄⸥ߒߚࠃ߁ߦޔ૏⋧ߩㆃࠇߪ χ ′′ ߦ㑐ㅪߔࠆ㗄ߢ޽ࠅޔ ω ߇ ዊߐߌࠇ߫ δ ߪ߶߷ 0 ߣߥࠆޕߟ߹ࠅߎߩ⁁ᴫਅߢߪޔ χ ′ ߪ㕒⏛႐ਅߢߩ⏛ൻ₸ χ ߣ৻⥌

ߔࠆߎߣ߇⍮ࠄࠇߡ޿ࠆޕ (2)-(5) ᑼࠍ↪޿ࠆߣޔ χ′ ෸߮ χ ′′ ߪએਅߩࠃ߁ߦ⸥ㅀߐࠇࠆޕ

( ^χ ) ( ^ω _ω ^δ ) ( ) ^δ ( ( ) ^δ ( ) ^δ )

µ + = = − = exp − = cos − + sin − exp

ˆ exp ˆ ˆ

1

0 0 0

0 0

0 0

j

H B H

B t

H t B

H

B …(6)

1 cos

0 0

0

−

′ = δ

χ µ

H

B …(7)

µ δ

χ sin

0 0

0

H

= B

′′ ^…(8)

ߟ߹ࠅޔ χ ′ ෸߮ χ ′′ ߪ⹜ᢱਛߩ⏛᧤ኒᐲ B ˆ _{ߩ੤ᵹ⏛႐} H ˆ ߣหߓ૏⋧ࠍᜬߟᚑಽߣޔ 90

^o

ߛߌ

૏⋧ߩㆃࠇߚᚑಽࠍ᷹ቯߔࠆߎߣߢ᳞߼ࠆߎߣ߇ߢ߈ࠆޕ 2.2 ੤ᵹ⏛᧤⸘ߩේℂ

੤ᵹ⏛᧤⸘ߢߪޔ੤ᵹ⏛႐ਅߢߩ⹜ᢱਛߩ⏛᧤ኒᐲߩᄌൻࠍ࠰࡟ࡁࠗ࠼ࠦࠗ࡞߳ߩ⺃ዉ

⿠㔚ജߣߒߡᬌ಴ߔࠆޕߘߩේℂࠍએਅߦ⺑᣿ߔࠆ [4] ޕ੤ᵹ⏛႐⊒↢↪ߣߒߡ↪޿ࠆඨᓘ

aޔ

㐳ߐ

lޔ

✢Ꮞ߈ᢙ

N1

ߩਛⓨߩ࠰࡟ࡁࠗ࠼ࠦࠗ࡞ 1 㧔࡝ࠕࠢ࠲ࡦࠬ

L1

㧕ߦએਅߩ੤ᵹ㔚࿶ V ˆ

₁

ࠍ ශടߔࠆޕ

t j V

V ˆ

₁

=

₀

exp ω ^…(9)

V0

ߪ੤ᵹ㔚࿶ߩᝄ᏷ߢ޽ࠆޕߎߩߣ߈࠰࡟ࡁࠗ࠼ࠦࠗ࡞ 1 ߦᵹࠇࠆ㔚ᵹ I ˆ

₁

ߪޔ

( )

2

(

1

)

1 2 1

0 1

1 0 1

1 1

exp exp

ˆ

ˆ ˆ ω θ

ω ω

ω −

= +

= +

= j t

L R

V L

j R

t j V Z

I V ޔ …(10)

ૉߒޔ R

L

₁

1

tan

1

ω

θ =

⁻

^…(11)

ߣߥࠆޕߎߎߢޔ Z ˆ

₁

ߪ࠰࡟ࡁࠗ࠼ࠦࠗ࡞ 1 ߩⶄ⚛ࠗࡦࡇ࡯࠳ࡦࠬޔR

1

ߪ࠰࡟ࡁࠗ࠼ࠦࠗ࡞

1 ߩ㔚᳇ᛶ᛫ߢ޽ࠆޕߎߩ㔚ᵹ I ˆ ߦࠃࠅޔ࠰࡟ࡁࠗ࠼ࠦࠗ࡞ 1 ߩ┵߆ࠄ〒㔌

x

ߩ႐ᚲߦ⊒↢

ߔࠆ⏛႐ H ˆ

₁

ߪޔⓨߩࠦࠗ࡞ਛߩ⏛᧤ኒᐲ B ˆ

₁

ࠃࠅએਅߩࠃ߁ߦᦠߌࠆޕ

( )

( ) ( )

2

(

1

)

1 2 1

0 2 2

2 2 1

2 2 2

2 1 0 1 1

2 exp 2

ˆ ˆ ˆ

θ ω ω

µ

+ −

 





 





− +

− −

= +

 





 





− +

− −

= +

=

t L j

R V x

l a

x l x

a x l

N

x l a

x l x

a x l

I N H B

…(12)

ߎߩ੤ᵹ⏛႐ߩਅߢ࠰࡟ࡁࠗ࠼ࠦࠗ࡞ 1 ߩਛᔃㇱ 㧔x =

l

/2 㧕ߦⶄ⚛⏛ൻ₸ χ ˆ

₁

ߩ⹜ᢱࠍኒߦߟ

߼ߚ႐วޔ⹜ᢱਛߩ⏛᧤ኒᐲ B ˆ

_1in

ߪએਅߩࠃ߁ߦᦠ߈⴫ߐࠇࠆޕ

( )

( )

( )

2

(

1

)

2 1 1

0 2

1 2 0

1 1 0 1

4 exp ˆ 2

1 ˆ ˆ ˆ 1

θ ω ω

χ µ

χ µ

+ − + +

= +

=

t L j

R V l

a N H B

_in

…(13)

ߎߩ⏛᧤ኒᐲߩᄌൻߦࠃࠅޔ࠰࡟ࡁࠗ࠼ࠦࠗ࡞ 1 ߦ㊀ߨߡᏎ޿ߚ࠰࡟ࡁࠗ࠼ࠦࠗ࡞ 2 ߦߪ

એਅߩ⺃ዉ⿠㔚ജ V ˆ

_2in

_{߇⊒↢ߔࠆޕ}

Coil 1

Coil 3

Coil 2

Lock-in Amplifier

Pd powder TMP

H₂ RP gas

Fig. 1. Schematic view of alternating current susceptometer and conventional PCT measurement system.

( )

( )

( ) ^{   − −   }

+ +

− +

=

−

=

exp 2 4

exp 2 1 ˆ

ˆ ˆ

2 1 2 1

1 0 2

2 1 0

2 1 2

θ π ω ω

ω δ µ

χ j t

L R

V l

a j NS dt

B S d

V

_in ⁱⁿ

…(14)

ߎߩᑼߪవ㗡ߩ᜝ᒐਛߩੑߟߩ㗄ߦಽߌࠄࠇޔ೨ߩ㗄ߪ੤ᵹ⏛႐߇⿠ߎߔ㧔⹜ᢱ߇ή޿႐ วߩ㧕 ⺃ዉ⿠㔚ജޔ ᓟߩ㗄ߪ⹜ᢱਛߩ⏛᧤ኒᐲߩᄌൻߦ⿠࿃ߒߚ⺃ዉ⿠㔚ജߣߥߞߡ޿ࠆޕ ߎࠇࠃࠅޔ⹜ᢱࠍ⹣߼ߚ㓙ߩ⺃ዉ⿠㔚ജ߆ࠄޔ⹜ᢱ߇ή޿႐วߩ⺃ዉ⿠㔚ജࠍᒁߊߎߣߦ ࠃࠅޔ⹜ᢱߩⶄ⚛⏛ൻ₸ߩᄢ߈ߐ χ ˆ

₁

෸߮૏⋧ߩߕࠇ δ 㧔ᚗ޿ߪ χ′ ෸߮ χ ′′ 㧕ߦ㑐ߔࠆᖱႎ ࠍᓧࠆߎߣ߇ߢ߈ࠆޕ

2.3 ੤ᵹ⏛᧤⸘ߩ᭎ⷐ

᷹ቯⵝ⟎ߩ᭎⇛ࠍ࿑ 1 ߦ␜ߔޕ࿑ਛߩ⎕✢ߢ࿐߹ࠇߚㇱಽ߇ޔ੹࿁᭴▽ߒߚ੤ᵹ⏛᧤⸘

ߢ޽ࠅޔߘߩઁߩㇱಽߪᣢሽߩ PCT ᷹ቯⵝ⟎ߢ޽ࠆޕ੤ᵹ⏛᧤⸘ࠍᣢሽߩ᳓⚛ๆ෼᡼಴᷹

ቯⵝ⟎ߦ⚵ߺㄟ߻㓙ߪޔ⹜ᢱ▤એᄖߪⵝ⟎ߩᡷㅧࠍᔅⷐߣߒߥ޿ޕ߹ߚޔ੤ᵹ⏛᧤⸘ߣ PCT

᷹ቯⵝ⟎ߪ੕޿ߦ⁛┙ߦ૶↪น⢻ߢ޽ࠆޕ

੤ᵹ⏛᧤⸘ߪ੤ᵹାภ⊒ାᯏ㧔 DF1906, NF ࿁〝⸳⸘ࡉࡠ࠶ࠢ㧕෸߮ࡠ࠶ࠢࠗࡦࠕࡦࡊ 㧔 Model 5210, SEIKO Instruments 㧕ޔߘߒߡౝᓘ 8 mm ޔᄖᓘ 10 mm ߩ⍹⧷▤ߦᏎ޿ߚ 3 ߟ ߩ࠰࡟ࡁࠗ࠼ࠦࠗ࡞ࠃࠅ᭴ᚑߐࠇࠆޕ࿑ 1 ਛߦ⸥タߒߚ੤ᵹ⏛᧤⸘ߩ࠰࡟ࡁࠗ࠼ࠦࠗ࡞ߩ ߁ߜޔᏀ஥ߩ࠰࡟ࡁࠗ࠼ࠦࠗ࡞ 1 ߇੤ᵹ⏛႐⊒↢↪ߢ޽ࠅޔฝ஥ߩ 2 ߟߩ࠰࡟ࡁࠗ࠼ࠦࠗ

࡞ 2 ޔ 3 ߇⹜ᢱߩ⺃ዉ⿠㔚ജ᷹ቯ↪ߢ޽ࠆޕ

࠰࡟ࡁࠗ࠼ࠦࠗ࡞ 2 ߣ 3 ߪޔ੤ᵹ⏛႐⊒↢

ᤨߦࠦࠗ࡞ߩਛ߇ⓨߩ⁁ᘒߢ߶߷หߓ಴

ജ߇ᓧࠄࠇޔ ਔ⠪ߩ಴ജߩᏅಽ߇߶߷ 0 ߦ ߥࠆࠃ߁ߦᏎ߈ᢙࠍ⺞ᢛߒߡ޽ࠆޕߟ߹ࠅ

⹜ᢱ᷹ቯᤨߪޔ  ᣇߩ࠰࡟ࡁࠗ࠼ࠦࠗ࡞ߦ

⹜ᢱࠍ㈩⟎ߒޔ߽߁ ᣇߩⓨߩ࠰࡟ࡁࠗ࠼

ࠦࠗ࡞߆ࠄ⊒↢ߔࠆ಴ജࠍᏅߒᒁߊߎߣ ߢޔ⹜ᢱߩ⏛ൻ₸ߦ⿠࿃ߒߚ⺃ዉ⿠㔚ജߩ ߺࠍขࠅ಴ߔޕߒ߆ߒታ㓙ߦߪޔⓨߩ⁁ᘒ ߢߩ࠰࡟ࡁࠗ࠼ࠦࠗ࡞ 2 ෸߮ 3 ߩ಴ജߪቢ

ోߦ৻⥌ߖߕޔ⚿ᨐߣߒߡਔ⠪ߩᏅಽߩ಴

ജࠍࡠ࠶ࠢࠗࡦࠕࡦࡊߢ᷹ቯߔࠆߣޔ৻ቯ ߩ⺃ዉ⿠㔚ജ V

_back

߇ᬌ಴ߐࠇࠆޕߟ߹ࠅታ 㓙ߦ⹜ᢱࠍ᷹ቯߒߚ႐วޔ ࠰࡟ࡁࠗ࠼ࠦࠗ

࡞ 2 ߦ⹜ᢱࠍ⸳⟎ߒ࠰࡟ࡁࠗ࠼ࠦࠗ࡞ 2 ߩ

಴ജ߆ࠄ࠰࡟ࡁࠗ࠼ࠦࠗ࡞ 3 ߩ಴ജࠍᏅߒ

ᒁ޿ߚ⺃ዉ⿠㔚ജ V

_2in

ࠍ᷹ቯߔࠆߣޔ

sample back

in

V V

V

₂

= + ^…(15)

ߣߥࠆޕߟ߹ࠅޔ V

_2in

ߪ⹜ᢱߦ⿠࿃ߒߚ⺃ዉ⿠㔚ജ V

_sample

ߦ V

_back

߇ടࠊߞߚ୯ߣߥࠆޕߎߩ V

_back

ࠍขࠅ㒰ߊߚ߼ޔ V

_2in

ࠍ᷹ቯߒߚᓟޔ⹜ᢱࠍ࠰࡟ࡁࠗ࠼ࠦࠗ࡞ 3 ߦ⒖േߒޔ V

_2in

ࠍ᷹ቯ ߒߚ႐วߣหߓࠃ߁ߦޔ࠰࡟ࡁࠗ࠼ࠦࠗ࡞ 2 ߩ಴ജ߆ࠄ࠰࡟ࡁࠗ࠼ࠦࠗ࡞ 3 ߩ಴ജࠍᏅߒ ᒁ޿ߚ⺃ዉ⿠㔚ജ V

_3in

ࠍ᷹ቯߔࠆޕ

sample back

in

V V

V

₃

= − ^{…(16 )}

(15) ᑼ෸߮ (16) ᑼࠃࠅޔ V

_2in

߆ࠄ V

_3in

ࠍᒁ޿ߚ୯∆ V ߪ V

_sample

ߩߺߩ಴ജߣߥࠆߎߣ߇ࠊ߆ࠆޕ ᧄ᷹ቯߢߪએ਄ߩᚻᴺࠍ↪޿ߡ∆ V ࠍ᷹ቯߒߚޕߘߩ㓙ޔ⹜ᢱ૏⟎ߩ⒖േߪ࠰࡟ࡁࠗ࠼ࠦࠗ

࡞ో૕ࠍ⒖േߔࠆߎߣߦࠃࠅⴕߞߚޕ߹ߚޔ੹࿁⺃ዉ⿠㔚ജߩᬌ಴ߦ↪޿ࠆࡠ࠶ࠢࠗࡦࠕ ࡦࡊߢߪޔ੤ᵹ㔚࿶ߩᝄ᏷෸߮ෳᾖାภ㧔ߎߎߢߪ࠰࡟ࡁࠗ࠼ࠦࠗ࡞ 1 ߦࠃࠅ⊒↢ߔࠆ੤

ᵹ⏛႐㧕߆ࠄߩ૏⋧ߩߕࠇࠍหᤨߦ᷹ቯน⢻ߢ޽ࠅޔߎߩᯏ⢻ࠍ↪޿ߡޔ χ′ ߦᲧ଀ߔࠆෳ

ᾖାภߣห૏⋧ߩ಴ജ∆ V

_x

ޔ߅ࠃ߮ χ ′′ ߦᲧ଀ߔࠆ 90

^O

ㆃࠇߚ૏⋧ߩ಴ജ∆ V

_y

ࠍ᳞߼ߚޕ 2.4 ੤ᵹ⏛᧤⸘ߩᩞᱜ

᷹ቯߒߚ⺃ዉ⿠㔚ജ߆ࠄ⏛ൻ₸߳ߩᄌ឵ߪޔ੍߼⏛ൻ₸߇ᣢ⍮ߢ޽ࠆᮡḰ⹜ᢱߦࠃࠅᓧ ࠄࠇࠆ⺃ዉ⿠㔚ജߣ⏛ൻ₸ߩ㑐ଥࠍ↪޿ߡ߅ߎߥߞߚޕ੹࿁ߪᮡḰ⹜ᢱߣߒߡ Gd

₂

O

₃

☳ᧃ ࠍ↪޿ߚޕᚲቯߩ㊀㊂ߩ Gd

₂

O

₃

☳ᧃࠍߟ߼ߚ㐳ߐ 10 mm ⒟ᐲߩ࠹ࡈࡠࡦ⵾ߩ╴ࠍޔ Gd

₂

O

₃

☳ᧃߩ㊀㊂ࠍᄌ߃ߡ 5 ⒳㘃૞ᚑߒޔߘࠇߙࠇߩ⺃ዉ⿠㔚ജࠍ᷹ቯߒߚޕ᷹ቯ଀ߣߒߡ Gd

₂

O

₃

☳ᧃ 45.4 mg ߩ᷹ቯᤨߩ⺃ዉ⿠㔚ജߩᄌൻࠍ࿑ 2 ߦ␜ߔޕ ࿑ 2 ߦ␜ߒߚ⺃ዉ⿠㔚ജߪ࠰࡟ࡁ

ࠗ࠼ࠦࠗ࡞ 2 ߆ࠄ࠰࡟ࡁࠗ࠼ࠦࠗ࡞ 3 ߩ಴ജࠍᏅߒᒁ޿ߚ୯ߢ޽ࠅޔᦝߦࡠ࠶ࠢࠗࡦࠕࡦ ࡊߦࠃࠅ੤ᵹ⏛႐ߣห૏⋧ߩ V

_x

ޔ෸߮૏⋧߇ 90

^O

ㆃࠇߚ V

_y

ࠍಽ㔌ߒߡ᷹ቯߒߚ⚿ᨐߢ޽ࠆޕ

߹ߚޔ࿑ 2 ߩԘߩ㗔ၞ߇࠰࡟ࡁࠗ࠼ࠦࠗ࡞ 2 ߦ⹜ᢱࠍ㈩⟎ߒߚ႐วߩ಴ജ㧔 (15) ᑼߩ V

_2in

ߦ

⋧ᒰ㧕ޔ ԙߩ㗔ၞ߇࠰࡟ࡁࠗ࠼ࠦࠗ࡞ 3 ߦ⹜ᢱࠍ㈩⟎ߒߚ႐วߩ಴ജ㧔 (16) ᑼߩ V

_3in

ߦ⋧ᒰ㧕 ߢ޽ࠆޕߎࠇࠃࠅޔ V

_back

ߣߒߡ V

_x

ߢ -510

µ

V ޔ V

_y

ߢ 280

µ

V ⒟ᐲߩ಴ജ߇޽ࠆߎߣ߇ࠊ߆ࠆޕ ߎࠇ߇࠰࡟ࡁࠗ࠼ࠦࠗ࡞ 2 ෸߮ 3 ߩࠕࡦࡃ࡜ࡦࠬಽߩ಴ജߣߥࠆޕ⹜ᢱߩ⏛ൻ₸ߦኻᔕߔ ࠆޔ ԘߣԙߩᏅಽ∆ V ߪޔ

∆

V

_x

ߢ 14.1

µ

V ಴ജߐࠇࠆߩߦኻߒߡޔ

∆

V

_y

ߢߪ߶ߣࠎߤ 0 ߣߥࠆޕ ߟ߹ࠅޔ੹࿁↪޿ߚ๟ᵄᢙߢߪޔ૏⋧ߩߕࠇߪ߶߷ 0 ߣߥࠅޔ V

_x

ࠃࠅ᳞߼ࠆ χ′ ߩ୯ߪ㕒⏛

႐ਅߢߩ⏛ൻ₸ χ ߦ߶߷৻⥌ߔࠆߣ޿߃ࠆޕߎߩ∆ V ߣ Gd

₂

O

₃

ߩ㊀㊂ߩ㑐ଥࠍ᷹ቯߒߚ⚿ᨐ ࠍ࿑ 3 ߦ␜ߔޕ᷹ቯߪฦ㊀㊂ߢ 5 ࿁ⴕߞߚޕߎߩ⚿ᨐࠃࠅޔ∆ V

_x

ߪ Gd

₂

O

₃

ߩ㊀㊂ߦኻߒߡ⋥

✢㑐ଥޔ∆ V

_y

ߪో㗔ၞߢ߶߷ 0 ߢ޽ࠆߣࠊ߆ࠆޕ∆ V

_x

ߩ⋥✢ࠍᦨዊੑਸ਼ᴺߦࠃࠅㄭૃߔࠆߎ ߣߢޔ࿑ 3 ਛߦ␜ߔᑼ߇ᓧࠄࠇߚޕ Gd

₂

O

₃

ߩ⏛ൻ₸ߪቶ᷷ߢ 1.74 ˜ 10

^-6

m

³

/kg ߢ޽ࠆߎߣ߇

⍮ࠄࠇߡ߅ࠅ [5] ޔߎߩ୯ߣᦨዊੑਸ਼ᴺߦࠃࠅᓧࠄࠇߚ⋥✢ߩᑼ߆ࠄޔਅ⸥ߩ⺃ዉ⿠㔚ജ∆ V

_x

(

µ

V) ߣ⏛ൻ₸ χ ^(m

³

^/kg) ߩ㑐ଥᑼࠍᓧߚޕ

( )

W V

_x

1 . 74 10 1

31292 . 0

10386 .

0 × ×

₆

×

−

= ∆

⁻

χ ^…(17)

ߎߎߢޔ W (mg) ߪ᷹ቯ⹜ᢱߩ㊀㊂ࠍ␜ߔޕ Pd ᳓⚛ൻ‛ߩ᷹ቯߦࠃࠅᓧࠄࠇߚ∆ V

_x

ߪߎߩᑼ

ࠍ↪޿ߡ⏛ൻ₸ߦᄌ឵ߒߚޕ߹ߚޔฦ㊀㊂ߢ᷹ቯߒߚ 5 ὐߩᮡḰ஍Ꮕࠍ᳞߼ࠆߣޔᦨᄢߢ

0.208

µ

V ߢ޽ߞߚޕᮡḰ஍Ꮕߩ 2 ୚ࠍಽ⸃⢻ߣߔࠆߣޔ Pd ᷹ቯᤨߢߩⵝ⟎ߩಽ⸃⢻ߪ਄ᑼ

ࠃࠅ 2.17 ˜ 10

^-9

m

³

/kg ߣ⷗Ⓧ߽ࠄࠇߚޕ 㧔㧡㧕 Pd ᳓⚛ൻ‛ߩ᷹ቯ

᷹ቯ⹜ᢱߢ޽ࠆ Pd 㧔 99.9 㧑ޔ࠾࡜ࠦ㧕ߪޔ᧼⁁ߩ߽ߩࠍ࠮࡜ࡒ࠶ࠢ߿ߔࠅߢ☳ᧃ⁁ߦട Ꮏߒߚ߽ߩࠍ↪޿ߚޕߘߩᓟޔ PCT ᷹ቯⵝ⟎ߦขࠅઃߌߚ⍹⧷࠮࡞ਛߦޔ⚂ 1 g ߩ☳ᧃ Pd ࠍ޿ࠇޔ࠮࡞ਛࠍ 5 ˜ 10

^-5

Pa એਅ߹ߢឃ᳇ߒߚޕߘߩᓟޔᵴᕈൻಣℂߣߒߡ 523 K ߢ 2 h ߩ ടᾲឃ᳇ࠍⴕ޿ޔ಄ළᓟߩ⁁ᘒࠍ᳓⚛Ớᐲ [H]/[Pd] = 0 ߣߒߚޕߎߎ߆ࠄ Pd ߦ৻ቯ㊂ߩ H

₂

ࠟࠬࠍዉ౉ߒޔ Pd ᳓⚛ൻ‛ߣ᳇⋧ߩ H

₂

ࠟࠬ߇ᐔⴧߦ㆐ߒߚߩߜߦޔ਄⸥ⵝ⟎ߦࠃࠅ Pd ᳓

⚛ൻ‛ߩ⺃ዉ⿠㔚ജࠍ᷹ቯߒߚޕߎࠇࠍޔ ᐔⴧ࿶߇ 0.1 MPa ⒟ᐲߦߥࠆ߹ߢ➅ࠅ㄰ߒⴕߞߚޕ

⺃ዉ⿠㔚ജߩ᷹ቯߪޔ 295 ~ 300 K ߩቶ᷷ߦߡޔ࠰࡟ࡁࠗ࠼ࠦࠗ࡞ 1 ߦ๟ᵄᢙ 487 Hz ޔ੤ᵹ ᝄ᏷ Vp-p 㧔ᦨᄢ୯ߣᦨዊ୯ߩᏅ㧕 10 V ߩ੤ᵹ㔚࿶ࠍශടߔࠆߎߣߢⴕߞߚޕ

3. ታ㛎⚿ᨐ

࿑ 4 ߦ੤ᵹ⏛᧤⸘ࠍ↪޿ߡ᷹ቯߒߚ Pd ᳓⚛ൻ‛ߩ∆ V

_x

෸߮∆ V

_y

ߩ᳓⚛Ớᐲଐሽᕈޔ෸߮ᐔ ⴧ࿶ߩ᳓⚛Ớᐲଐሽᕈࠍ␜ߔޕ Pd ߩᐔⴧ࿶ߪ [H]/[Pd] = 0.05 એ਄ 0.6 ᧂḩߢ߶߷৻ቯߩ୯ࠍ

␜ߒޔ [H]/[Pd] > 0.6 ߢᕆỗߦჇടߒߚޕߎߩ௑ะߪㆊ෰ߦ᷹ቯߐࠇߚ⚿ᨐ [6] ߣࠃߊ৻⥌ߒ

ߚޕ

ᐔⴧ࿶ߣหᤨߦ᷹ቯߒߚ∆ V

_x

߅ࠃ߮∆ V

_y

ߦߟ޿ߡߪޔ∆ V

_x

ߪ᳓⚛Ớᐲ߇㜞ߊߥࠆߦᓥ޿න

⺞ߦᷫዋߒޔ [H]/[Pd] = 0.65 ߢߪ߶߷ 0 ߦ೔㆐ߒߚޕ߹ߚޔߘࠇએ਄ߩ᳓⚛Ớᐲߢߪ∆ V

_x

ߪ Fig. 2. Typical measurement result of

in-phase and out-of-phase output voltage for 45.4 mg Gd

₂

O

₃

powder.

Fig. 3. Gd

₂

O

₃

weight dependence of output signal,

∆

V

_x

and

∆

V

_y

. The dashed line shows the result by least squared fit to

∆

V

_x

.

-520 -515 -510 -505 -500

270 275 280 285 290

0 100 200 300 400 500 600

Gd2O

3 powder (45.4 mg)

output voltage, V x / µV output voltage, V y / µV

time, t / sec

f = 487 Hz, Vp-p = 10 V, 295 K

∆V_x

㽲 㽳

0 2 4 6 8 10 12 14 16

0 2 4 6 8 10 12 14 16

0 10 20 30 40 50

Gd₂O₃ powder

y = 0.10386 + 0.31292x , R= 0.99913

output signal, ∆V x_Gd2O3 / µV

Gd2O

3 weight, w

Gd2O3 / mg

output signal, ∆V Y_Gd2O3 / µV

ᄌൻߒߥ߆ߞߚޕ৻ᣇޔ∆ V

_y

ߪ [H]/[Pd] = 0.2 ⒟ᐲ߹ߢ߶߷৻ቯߢ޽ࠅޔ 0 ߢߪߥ޿᦭㒢ߩ୯ ࠍ␜ߒߚޕ [H]/[Pd] > 0.2 ߢߪޔ∆ V

_y

ߪ [H]/[Pd] ߩჇടߦᓥ޿න⺞ᷫዋߒޔ∆ V

_x

߇߶߷ 0 ߣߥࠆ

[H]/[Pd] = 0.65 એ਄ߦ߅޿ߡ߽න⺞ᷫዋߒ 0 ߦߪߥࠄߥ߆ߞߚޕ೨ㅀߒߚࠃ߁ߦޔ੹࿁ታ㛎

ߢ↪޿ߚ੤ᵹ⏛႐ߩᝄേᢙߪචಽዊߐ޿ߣ⠨߃ࠄࠇޔ߹ߚ Pd ߪ Pauli Ᏹ⏛ᕈߢ޽ࠅᄢ߈ߥ

⏛᳇ࡕ࡯ࡔࡦ࠻ࠍᜬߚߥ޿ߎߣ߆ࠄޔ

∆

V

_y

= 0 ࠍ␜ߔߪߕߢ޽ࠆޕߎߩ∆ V

_y

߇᦭㒢ߩ୯ࠍ␜ߔ

ේ࿃ߣߒߡޔ੤ᵹ⏛႐ਛߦ߅޿ߡ⹜ᢱਛߦ⊒↢ߔࠆ⺃ዉ㔚ᵹߦࠃࠆᓇ㗀߇⠨߃ࠄࠇࠆޕߟ

߹ࠅޔ Pd ᳓⚛ൻ‛ߩ᳓⚛Ớᐲ߇Ⴧടߔࠆߎߣߢ Pd ☳ᧃ߇⤘ᒛߒ☳ᧃห჻ߩ⚿ว߇ᡷༀߐࠇ ࠆߚ߼ޔ⺃ዉ㔚ᵹߩࡄࠬ߇㐳ߊ᭴▽ߢ߈ࠆࠃ߁ߦߥࠅޔ⚿ᨐߣߒߡ⺃ዉ㔚ᵹߦࠃࠅ⊒↢ߔ ࠆ⏛᧤߇ᄢ߈ߊߥࠆߚ߼ߢߪߥ޿߆ߣផኤߢ߈ࠆޕૉߒޔߎࠇࠄߩ⸃ᨆߪᦝߥࠆ⹦⚦ߥ᷹

ቯ෸߮⸃ᨆ߇ᔅⷐߣߥࠆߚ߼ޔ⃻ᤨὐߢߪߎࠇએ਄ߩᬌ⸛ߪⴕࠊߥ޿ޕ

࿑ 5 ߦ (17) ᑼࠍ↪޿ߡ∆ V

_x

ߩ୯ࠍ⏛ൻ₸ χ ߦᄌ឵ߒߚ⚿ᨐࠍ␜ߔޕ޽ࠊߖߡ SQUID ⏛᧤

⸘ࠍ↪޿ߡ᷹ቯߐࠇߚㆊ෰ߩ᷹ቯ⚿ᨐ [7] ࠍ␜ߒߚޕ੹࿁᷹ቯߐࠇߚ⚿ᨐߣޔㆊ෰ߦ᷹ቯߐ ࠇߚ⚿ᨐߪޔቯ㊂⊛ߦࠃߊ৻⥌ߒߚޕએ਄ࠃࠅޔ੹࿁᭴▽ߒߚ੤ᵹ⏛᧤⸘ߦࠃࠅ᳓⚛ൻ‛

ߩ⏛ൻ₸߇᷹ቯน⢻ߢ޽ࠆߎߣ߇␜ߐࠇߚޕ

4. ߹ߣ߼

㊄ዻ᳓⚛ൻ‛᷹ቯ↪੤ᵹ⏛᧤⸘ࠍ૞⵾ߒޔߘߩᕈ⢻⹏ଔࠍⴕߞߚޕ૞⵾ߒߚ੤ᵹ⏛᧤⸘

ߪޔ⹜ᢱࠍ᳓⚛㔓࿐᳇ࠃࠅขࠅ಴ߔߎߣήߊ᷹ቯ߇ߢ߈ࠆࠃ߁ޔᣢሽߩ PCT ᷹ቯⵝ⟎ࠍᡷ ㅧߖߕߦขࠅઃߌࠄࠇࠆࠃ߁⸳⸘ߒߚޕ Gd

₂

O

₃

☳ᧃࠍ↪޿ߡ⏛᧤⸘ߩᩞᱜࠍⴕߞߚߣߎࠈޔ

᷹ቯ㔚࿶ߣ Gd

₂

O

₃

㊀㊂ߩ㑆ߢࠃ޿⋥✢㑐ଥ߇ᓧࠄࠇޔߎࠇࠃࠅޔ᷹ቯ㔚࿶߆ࠄ⏛ൻ₸߳ߩ ᄌ឵ᑼ෸߮⏛᧤⸘ߩಽ⸃⢻ 2.17 ˜ 10

^-9

m

³

/kg ߇ᓧࠄࠇߚޕᧄⵝ⟎ࠍ↪޿ߡ Pd ᳓⚛ൻ‛ߩ⏛

ൻ₸᷹ቯࠍⴕߞߚ⚿ᨐޔㆊ෰ߦႎ๔ߐࠇߚ୯ߣቯ㊂⊛ߦࠃߊ৻⥌ߒߚޕએ਄ࠃࠅޔ੤ᵹ⏛

᧤⸘ࠍ↪޿ߚ㊄ዻ᳓⚛ൻ‛ߩ⏛ൻ₸᷹ቯ߇චಽน⢻ߢ޽ࠆߎߣ߇␜ߐࠇߚޕ Fig. 4. Hydrogen concentration dependence

of output signal and equilibrium pressure for Pd hydride. The dashed line for equilibrium pressure is guide to the eye.

Fig. 5. Hydrogen concentration dependence of magnetic susceptibility of Pd hydride. The figure includes the data reported by Hara et al.[5]

0 10 20 30 40 50 60 70

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 our work Hara et al.

magnetic susceptibility,χ' / 10-9 m3 /kg

[H]/[Pd]

-10 -5 0 5 10 15

0.1 1 10 100

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7

output voltage, ∆Vx,∆Vy / µV equilibrium pressure, P / kPa

[H]/[Pd]

∆V_x

∆V_y P

Reference

[1] K. Fukamichi, A. Fujita, and S Fujieda, Journal of Alloys and Compounds

408-412

(2006) 307-312.

[2] F. J. A. den Broeder, S. J. van der Molen, M. Kremers, J. N. Huiberts, D. G. Nagengast, A. T.

M. van Gogh, W. H. Huisman, N. J. Koeman, B. Dam, J. H. Rector, S. Plota, M. Haaksma, R. M.

N. Hanzen, R. M. Jungblut, P. A. Duine, and R. Griessen, Natute

394

(1998) 656-658.

[3] ᣣᧄൻቇળ✬ޔᣂታ㛎⑼ቇ⻠ᐳ 3 ၮ␆ᛛⴚ 2 ⏛᳇㧔ਣༀޔ 1976 㧕 p.97-109.

[4] M. Nikolo, American Journal of Physics

63

(1995) 57-65.

[5] L. Sagnotti, P. Rochette, M. Jackson, F. Vadeboin, J. Dinarès-Turell, A. Winkler, and

“Mag-Net” Science Team, Physics of the Earth and Planetary Interiors

138

(2003) 25-38.

[6] E. Wicke and H. Brodowsky: G. Alefeld and J. Völkl (Eds.), Hydrogen in Metals II.

Application-oriented Properties, (Springer-Verlag, Berlin, 1978).

[7] M. Hara, J. Sakurai, S. Akamaru, K. Watanabe, K. Nishimura, K. Mori, M. Matsuyama,

Materials Transactions

47

(2006) 2373-2376.