Muroran-IT Academic Resources Archive Title カゴ状希土類化合物におけるラットリング効果による熱 伝導率低減機構の解明 Author(s) 関根, ちひろ; 川村, 幸裕; 武田, 圭生; 澤口, 直哉; 酒井, 彰; 中根, 英章 Citation Issue Date URL 室蘭工業大学紀要 Vol.63, pp.3-7, 2014 2014-03-18 http://hdl.handle.net/10258/2821 Rights Type Journal Article See also Muroran-IT Academic Resources Archive Copyright Policy Muroran Institute of Technology 63 号（2013） 3~7 ᐊᕤ⣖せ➨ ྕ㸦㸧㹼 室工大紀要第 特 集 ࢝ࢦ≧ᕼᅵ㢮ྜ≀࠾ࡅࡿࣛࢵࢺࣜࣥࢢຠᯝ ࡼࡿ⇕ఏᑟ⋡పῶᶵᵓࡢゎ᫂ 㛵᰿ ࡕࡦࢁ*1, *2㸪ᕝᮧ ᖾ⿱*2㸪Ṋ⏣ ᆂ⏕*1, *2㸪⃝ཱྀ ┤ဢ*1, *2㸪㓇 ᙲ*3, *2, ୰᰿ ⱥ❶*1, *2 Mechanism of Thermal Conductivity Reduction by Rattling Effect in Rare Earth Compounds with Cage-Like Structure Chihiro SEKINE*1, *2, Yukihiro KAWAMURA*2, Keiki TAKEDA*1, *2, Naoya SAWAGUCHI*1, *2 Akira SAKAI*3, *2, and Hideaki NAKANE*1, *2 㸦ཎ✏ཷ᪥ ᖹᡂ 25 ᖺ 9 ᭶ 30 ᪥ ㄽᩥཷ⌮᪥ ᖹᡂ 26 ᖺ 1 ᭶ 24 ᪥㸧 Abstract Rare earth compounds with a cage-like structure have been actively studied as potentially useful thermoelectric material because the compounds are believed to have low lattice conductivity due to a local anharmonic vibration of guest ions inside the cage. We have synthesized new skutterudite compounds, which are typical materials with a cage–like structure, and investigate their crystallographic, transport, thermoelectric properties in order to elucidate the mechanism of thermal conductivity reduction by local anharmonic phonons (rattling effect). We report some experimental evidences about rattling motion in skutterudite compounds and discuss the mechanism. Keywords : Thermoelectric material㸪High pressure synthesis㸪Rattling㸪Anharmonic phonon NL ࡢ࡛⾲ࡉࢀࡿ㸬⇕㟁ኚᮦᩱࡢᛶ⬟ᣦᩘ Z 1 ࡣࡌࡵ ࡣ ᗘࡢ㏫ᩘࡢḟඖࢆᣢࡗ࡚࠸ࡿࡢ࡛㸪㏻ᖖ㸪⤯ ⇕㟁ኚᮦᩱࡣ㸪⇕࢚ࢿࣝࢠ࣮ࢆ㟁Ẽ࢚ࢿࣝࢠ ᑐ ᗘ T [K]ࢆࡅࡓ↓ḟඖᛶ⬟ᣦᩘ ZT ࡀ⏝࠸ࡽ ࣮┤᥋ኚ࡛ࡁࡿᮦᩱ࡛࠶ࡾ㸪ᗫ⇕➼ࢆ⏝ࡋ ࢀ㸪ZT > 1 ࡀᐇ⏝ࡢ┠Ᏻࡉࢀ࡚࠸ࡿ㸬(1) ᘧࡼ ࡓ ᗘᕪⓎ㟁⏝࡛ࡁࡿ㸬ࡋࡋ㸪ࡇࡢⓎ㟁ᢏ ࡾ㸪㧗࠸ᛶ⬟ᣦᩘ Z ࢆᐇ⌧ࡍࡿࡓࡵࡣ㸪S ࡀࡁ ⾡ࢆᬑཬࡉࡏࡿࡓࡵࡣ㸪ᮦᩱࡢኚຠ⋡ࢆࡁ ࡃ㸪U㸪Nࡀᑠࡉ࠸ᮦᩱࢆ㛤Ⓨ࡛ࡁࢀࡤⰋ࠸ࡢࡔࡀ㸪 ࡃྥୖࡉࡏࡿࡇࡀㄢ㢟࡞ࡗ࡚࠸ࡿ㸬⇕㟁ኚ S㸪U㸪NE ࡣ࠸ࡎࢀࡶ࢟ࣕࣜ⃰ᗘࡢ㛵ᩘ࡛࠶ࡾ㸪S ᮦᩱࡢᛶ⬟ࡣ㸪௨ୗࡢᛶ⬟ᣦᩘ Z [1/K]࠸࠺ᣦᶆ U㸪NE ࡣ࠸ࢺ࣮ࣞࢻ࢜ࣇࡢ㛵ಀ࠶ࡿࡓࡵ㸪 ࡛⾲ࡉࢀࡿ㸬 ࡑࡢᐇ⌧ࡣᐜ࡛᫆ࡣ࡞࠸㸬୍᪉㸪᱁Ꮚ⇕ఏᑟ⋡ NL ࡣ࢟ࣕࣜ⃰ᗘ㛵ಀ࡞ࡃ⤖ᬗᵓ㐀➼࡛Ỵࡲࡿࡓ Z = S2 / U N 㺃㺃㺃㺃㺃㺃㺃㺃㺃㺃㺃㺃㺃㺃㺃㺃㺃㺃㺃㺃㺃㺃(1) ࡵ㸪⊂❧ไᚚࡍࡿࡇࡀྍ⬟࡛࠶ࡿ㸬᭱㏆㸪ࡇ ࡢⅬ╔┠ࡋࡓᮦᩱ㛤Ⓨࡀ⾜ࢃࢀ࡚࠸ࡿ㸬 ࡇࡇ࡛㸪S [V/K]ࡣࢮ࣮࣋ࢵࢡಀᩘ㸪U [:m]ࡣ㟁Ẽ ሸࢫࢡࢵࢸࣝࢲࢺ㸪ࢡࣛࢫ࣮ࣞࢺ㸪ࣃࣟ ᢠ⋡㸪N [W/mK]ࡣ⇕ఏᑟ⋡࡛࠶ࡿ㸬ࡉࡽ㸪⇕ ࢡࣟ࡞⤖ᬗᵓ㐀୰㧗ᑐ⛠ࡢ࢝ࢦ≧ᵓ㐀ࢆ᭷ ఏᑟ⋡ N ࡣ㟁Ꮚ⣔ࡼࡿᐤNE ᱁Ꮚ⣔ࡼࡿᐤ ࡍࡿᕼᅵ㢮ྜ≀࡛ࡣ㸪࢝ࢦෆ㒊ᙅࡃ⤖ྜࡋࡓ ࢤࢫࢺ࢜ࣥ㸦ᕼᅵ㢮࢜ࣥ㸧ࡀᕧᖜࡢᒁᡤ *1 ᐊ⹒ᕤᴗᏛ ࡶࡢ㐀⣔㡿ᇦ ⓗ࡞⊂❧ື㸦ᒁᅾ㠀ㄪࣇ࢛ࣀࣥ࠶ࡿ࠸ࡣࣛࢵ *2 ᐊ⹒ᕤᴗᏛ ⎔ቃㄪᮦᩱᕤᏛ◊✲ࢭࣥࢱ࣮ ࢺࣜࣥࢢࡤࢀࡿ㸧ࡍࡿࡇࡼࡾ㸪ㄪࣇ࢛ *3 ᐊ⹒ᕤᴗᏛ ࡋࡃࡳሗ⣔㡿ᇦ ࣀࣥࡼࡿ⇕ࡢఏࢆጉࡆ㸪᱁Ꮚ⇕ఏᑟ⋡NL ࢆⴭ -3－ 3 － 㛵᰿ࡕࡦࢁ㸪ᕝᮧᖾ⿱㸪Ṋ⏣ᆂ⏕㸪⃝ཱྀ┤ဢ㸪㓇ᙲ୰᰿ⱥ❶ 㛵᰿ࡕࡦࢁ㸪ᕝᮧᖾ⿱㸪Ṋ⏣ᆂ⏕㸪⃝ཱྀ┤ဢ㸪㓇ᙲ୰᰿ⱥ❶ ࡋࡃపῶࡉࡏࡿ⪃࠼ࡽࢀ࡚࠸ࡿ㸬ࡇࡢࣛࢵࢺࣜ (a) (a) ࣥࢢຠᯝࢆ㢧ⴭ♧ࡍᮦᩱ⣔ࢆ⏝ࡋࡓ㧗ᛶ⬟⇕ ࡋࡃపῶࡉࡏࡿ⪃࠼ࡽࢀ࡚࠸ࡿ㸬ࡇࡢࣛࢵࢺࣜ 㟁ኚᮦᩱࡢ㛤Ⓨࡀὀ┠ࡉࢀ࡚࠸ࡿ㸬᱁Ꮚ⇕ఏᑟ ࣥࢢຠᯝࢆ㢧ⴭ♧ࡍᮦᩱ⣔ࢆ⏝ࡋࡓ㧗ᛶ⬟⇕ ⋡ࡢపῶࡣ㸪࢟ࣕࣜ⃰ᗘࡢ᭱㐺ࡣ⊂❧⇕ 㟁ኚᮦᩱࡢ㛤Ⓨࡀὀ┠ࡉࢀ࡚࠸ࡿ㸬᱁Ꮚ⇕ఏᑟ 㟁≉ᛶࡢྥୖࡀྍ⬟࡞᪉ἲ࡛࠶ࡾ㸪㣕㌍ⓗ࡞ᛶ⬟ ⋡ࡢపῶࡣ㸪࢟ࣕࣜ⃰ᗘࡢ᭱㐺ࡣ⊂❧⇕ ྥୖࡘ࡞ࡀࡿྍ⬟ᛶࡀ㧗࠸㸬 㟁≉ᛶࡢྥୖࡀྍ⬟࡞᪉ἲ࡛࠶ࡾ㸪㣕㌍ⓗ࡞ᛶ⬟ X X ྥୖࡘ࡞ࡀࡿྍ⬟ᛶࡀ㧗࠸㸬 2 ࢫࢡࢵࢸࣝࢲࢺྜ≀ M M 2 ࢫࢡࢵࢸࣝࢲࢺྜ≀ ࢫࢡࢵࢸࣝࢲࢺྜ≀ࡣ㸪ࣛࢵࢺࣜࣥࢢຠᯝ ࡼࡾඃࢀࡓ⇕㟁≉ᛶࢆ♧ࡍᮦᩱ⣔ࡋ࡚ᮇᚅࡉ ࢫࢡࢵࢸࣝࢲࢺྜ≀ࡣ㸪ࣛࢵࢺࣜࣥࢢຠᯝ ࢀ࡚࠸ࡿ㸬ࢫࢡࢵࢸࣝࢲࢺྜ≀ࡣ㸪ඖ⣔ ࡼࡾඃࢀࡓ⇕㟁≉ᛶࢆ♧ࡍᮦᩱ⣔ࡋ࡚ᮇᚅࡉ MX3 ࡢ㠀ሸࢫࢡࢵࢸࣝࢲࢺྜ≀୕ඖ⣔ࡢሸ ࢀ࡚࠸ࡿ㸬ࢫࢡࢵࢸࣝࢲࢺྜ≀ࡣ㸪ඖ⣔ ࢫࢡࢵࢸࣝࢲࢺྜ≀ࡢ 2 ✀㢮ࡀᏑᅾࡍࡿ㸬ᅗ 1 ࡢ㠀ሸࢫࢡࢵࢸࣝࢲࢺྜ≀୕ඖ⣔ࡢሸ MX3 (b) (b) ⤖ᬗᵓ㐀ࢆ♧ࡍ㸬ࡕࡽࡢྜ≀ࡶయᚰ❧᪉ᬗ ࢫࢡࢵࢸࣝࢲࢺྜ≀ࡢ 2 ✀㢮ࡀᏑᅾࡍࡿ㸬ᅗ 1 ⣔࡛㸪✵㛫⩌ Im 3 㸦T5h㸧࡛࠶ࡿ㸬㠀ሸࢫࢡࢵࢸ ⤖ᬗᵓ㐀ࢆ♧ࡍ㸬ࡕࡽࡢྜ≀ࡶయᚰ❧᪉ᬗ ࣝࢲࢺྜ≀ 㸦ᅗ 1a㸧 Rh, 3 hࡣ୍⯡ᙧࡀ MX㸦M=Co, 3 㸦T ⣔࡛㸪✵㛫⩌ Im 5 㸧࡛࠶ࡿ㸬㠀ሸࢫࢡࢵࢸ Ir, Ni ; X=P, As, Sb㸧ࡲࡓࡣ ڧM4XMX 12㸦✵=ڧ㝽㸧 ࣝࢲࢺྜ≀ 㸦ᅗ 1a㸧ࡣ୍⯡ᙧࡀ 㸦M=Co, Rh, 3 ࡛⾲ࡉࢀ㸪3 ඖ⣔ࡢሸࢫࢡࢵࢸࣝࢲࢺྜ≀ Ir, Ni ; X=P, As, Sb㸧ࡲࡓࡣ ڧM4X12㸦✵=ڧ㝽㸧 㸦ᅗ 1b㸧ࡣ㸪୍⯡⣔ࢆ RT4X12㸦R=ࣝ࢝ࣜᅵ㢮ඖ ࡛⾲ࡉࢀ㸪3 ඖ⣔ࡢሸࢫࢡࢵࢸࣝࢲࢺྜ≀ X X ⣲㸪 ࢡࢳࣀࢻඖ⣲࡞㸪T=Fe, Ru, 㸦ᅗᕼᅵ㢮ඖ⣲㸪 1b㸧ࡣ㸪୍⯡⣔ࢆ RT4X12㸦R=ࣝ࢝ࣜᅵ㢮ඖ Os, Pt; X=P, As, Sb,ࢡࢳࣀࢻඖ⣲࡞㸪T=Fe, Ge㸧࡛⾲ࡉࢀࡿ㸬ሸࢫࢡࢵࢸ ⣲㸪 ᕼᅵ㢮ඖ⣲㸪 Ru, ࣝࢲࢺྜ≀ࡣ T, X ཎᏊ࡛ᵓᡂࡉࢀࡿ᱁Ꮚࡢ Os, Pt; X=P, As, Sb, Ge㸧࡛⾲ࡉࢀࡿ㸬ሸࢫࢡࢵࢸ ࢝ࢦࡢ୰࡛ᙅࡃ⤖ྜࡋࡓ R ཎᏊࡀᕧᖜࡢᒁᡤ ࣝࢲࢺྜ≀ࡣ T, X ཎᏊ࡛ᵓᡂࡉࢀࡿ᱁Ꮚࡢ ⓗ࡞⊂❧ື㸦ࣛࢵࢺࣜࣥࢢ㸧ࡍࡿࡇࡼࡾ㸪 ࢝ࢦࡢ୰࡛ᙅࡃ⤖ྜࡋࡓ R ཎᏊࡀᕧᖜࡢᒁᡤ ᱁Ꮚ⇕ఏᑟ⋡ࡀⴭࡋࡃᢚไࡉࢀࡿ⪃࠼ࡽࢀ࡚࠸ ⓗ࡞⊂❧ື㸦ࣛࢵࢺࣜࣥࢢ㸧ࡍࡿࡇࡼࡾ㸪 ࡿ㸬ࣛࢵࢺࣜࣥࢢࡢᐇ㦂ⓗドᣐࡋ࡚㸪⤖ᬗᵓ㐀 ᱁Ꮚ⇕ఏᑟ⋡ࡀⴭࡋࡃᢚไࡉࢀࡿ⪃࠼ࡽࢀ࡚࠸ ࣃ࣓࣮ࣛࢱࡢ୍ࡘ࡛࠶ࡿ⇕ືࣃ࣓࣮ࣛࢱࡀ࠶ࡿ㸬 ࡿ㸬ࣛࢵࢺࣜࣥࢢࡢᐇ㦂ⓗドᣐࡋ࡚㸪⤖ᬗᵓ㐀 ⤖ᬗࢆᵓᡂࡍࡿࡢ࢜ࣥẚ࡚㸪࢝ࢦᵓ㐀ࡢ ࣃ࣓࣮ࣛࢱࡢ୍ࡘ࡛࠶ࡿ⇕ືࣃ࣓࣮ࣛࢱࡀ࠶ࡿ㸬 ෆ㒊࠶ࡿࢤࢫࢺ࢜ࣥࡢ⇕ືࣃ࣓࣮ࣛࢱࡀ㠀 ⤖ᬗࢆᵓᡂࡍࡿࡢ࢜ࣥẚ࡚㸪࢝ࢦᵓ㐀ࡢ ᖖࡁ࡞್ࢆ♧ࡍሙྜࡀ࠶ࡾ㸪ࡇࢀࡀࣛࢵࢺࣜ ෆ㒊࠶ࡿࢤࢫࢺ࢜ࣥࡢ⇕ືࣃ࣓࣮ࣛࢱࡀ㠀 ࣥࢢࡢᏑᅾࢆ♧၀ࡋ࡚࠸ࡿ㸬ࡲࡓ㸪ࣥࢩࣗࢱ ᖖࡁ࡞್ࢆ♧ࡍሙྜࡀ࠶ࡾ㸪ࡇࢀࡀࣛࢵࢺࣜ ᅗ 1 㠀ሸࢫࢡࢵࢸࣝࢲࢺྜ≀ MX3㸦a㸧 RT4X12 X ሸࢫࢡࢵࢸࣝࢲࢺྜ≀ RT 4 12㸦b㸧ࡢ ᅗ 1 㠀ሸࢫࢡࢵࢸࣝࢲࢺྜ≀ MX3㸦a㸧 ⤖ᬗᵓ㐀 ሸࢫࢡࢵࢸࣝࢲࢺྜ≀ RT4X12㸦b㸧ࡢ ⤖ᬗᵓ㐀 ẚ㍑ࡼࡾ㸪᱁Ꮚ⇕ఏᑟ⋡ࡢపῶᶵᵓࢆゎ᫂ࡍࡿ ࡇࢆ┠ⓗࡋࡓ㸬 3 ◊✲ᡭἲ CeRu 4Sb12 㛵ࡍࡿ୰ᛶᏊ㠀ᙎᛶᩓᐇ㦂ࡼࡿ ⪃࠼ࡽࢀ࡚࠸ࡿ㸬ሸࢫࢡࢵࢸࣝࢲࢺྜ≀ 㸪ࢤࢫࢺ࢜ࣥࡢ㠀ㄪᛶࡣ☜ㄆࡉࢀࡎ㸪࢝ࢦ CeRu Sb 㛵ࡍࡿ୰ᛶᏊ㠀ᙎᛶᩓᐇ㦂ࡼࡿ 12 3.1 ヨᩱྜᡂ (1)㸪 ࡢ┦స⏝ࡀ࠶ࡿࡇࡀᣦࡉࢀ࡚࠸ࡿࡀ ࢤ 㸪ࢤࢫࢺ࢜ࣥࡢ㠀ㄪᛶࡣ☜ㄆࡉࢀࡎ㸪࢝ࢦ ࢫࢺ࢜ࣥࡢື㛵㐃ࡍࡿపບ㉳ࡢගᏛࣇ࢛ࣀ ࡢ┦స⏝ࡀ࠶ࡿࡇࡀᣦࡉࢀ࡚࠸ࡿࡀ(1)㸪ࢤ 3 ◊✲ᡭἲ ᪂つሸࢫࢡࢵࢸࣝࢲࢺྜ≀ࡢከ⤖ᬗヨᩱ 3.1 ヨᩱྜᡂ ࡢྜᡂࡣ㸪㧗 㧗ᅽྜᡂἲࢆ⏝࠸㸪❧᪉యࡢᅽ ᪂つሸࢫࢡࢵࢸࣝࢲࢺྜ≀ࡢከ⤖ᬗヨᩱ ࣥࡣほ ࡉࢀ࡚࠾ࡾ㸪ࡇࢀࡀప࠸⇕ఏᑟ⋡ᐤ ࢫࢺ࢜ࣥࡢື㛵㐃ࡍࡿపບ㉳ࡢගᏛࣇ࢛ࣀ ࡋ࡚࠸ࡿࡇࡣ㛫㐪࠸࡞࠸ᛮࢃࢀࡿ㸬ࡑࡇ࡛㸪 ࣥࡣほ ࡉࢀ࡚࠾ࡾ㸪ࡇࢀࡀప࠸⇕ఏᑟ⋡ᐤ ຊ፹యࢆ 6 ᪉ྥࡽᆒ➼ຍᅽ࡛ࡁࡿ DIA ᆺ࢟ࣗ ࡢྜᡂࡣ㸪㧗 㧗ᅽྜᡂἲࢆ⏝࠸㸪❧᪉యࡢᅽ ࣮ࣅࢵࢡࣥࣅࣝ⨨㸦UHP500㸧࠾ࡼࡧṇඵ㠃య ຊ፹యࢆ 6 ᪉ྥࡽᆒ➼ຍᅽ࡛ࡁࡿ DIA ᆺ࢟ࣗ ࡢᅽຊ፹యࢆ 8 ᪉ྥࡽᆒ➼ຍᅽ࡛ࡁࡿᕝᆺ ࣮ࣅࢵࢡࣥࣅࣝ⨨㸦UHP500㸧࠾ࡼࡧṇඵ㠃య ᮏㄽᩥ࡛ࡣ㸪ࢤࢫࢺ࢜ࣥࡀࡁࡃㄪືࡍࡿ ࡋ࡚࠸ࡿࡇࡣ㛫㐪࠸࡞࠸ᛮࢃࢀࡿ㸬ࡑࡇ࡛㸪 ࡇࡶྵࡵ࡚㸪ࣛࢵࢺࣜࣥࢢࡪࡇࡍࡿ㸬 ᮏㄽᩥ࡛ࡣ㸪ࢤࢫࢺ࢜ࣥࡀࡁࡃㄪືࡍࡿ 2 ẁᘧ࣐ࣝࢳࣥࣅࣝ⨨(UHP1500)ࡢ 2 ྎࡢᆺ ࡢᅽຊ፹యࢆ 8 ᪉ྥࡽᆒ➼ຍᅽ࡛ࡁࡿᕝᆺ ࣉࣞࢫࢆ⏝࠸ࡓ㸬ྜᡂ᮲௳ࡣ 2ࠥ5GPa㸪 ᗘ 550 2 ẁᘧ࣐ࣝࢳࣥࣅࣝ⨨(UHP1500)ࡢ 2 ྎࡢᆺ ᮏ◊✲࡛ࡣ㸪㢧ⴭ࡞ࣛࢵࢺࣜࣥࢢຠᯝࡀᮇᚅࡉ ࡇࡶྵࡵ࡚㸪ࣛࢵࢺࣜࣥࢢࡪࡇࡍࡿ㸬 ࢀࡿ᪂ࡋ࠸≀㉁ࢆ᥈⣴࣭〇ࡋ㸪ᐇ㦂ⓗᒁᅾ㠀 ᮏ◊✲࡛ࡣ㸪㢧ⴭ࡞ࣛࢵࢺࣜࣥࢢຠᯝࡀᮇᚅࡉ ࠥ1100Υ࡛࠶ࡿ㸬 ࣉࣞࢫࢆ⏝࠸ࡓ㸬ྜᡂ᮲௳ࡣ 2ࠥ5GPa㸪 ᗘ 550 ㄪࣇ࢛ࣀࣥࡢᏑᅾࢆ☜ㄆࡋ㸪᱁Ꮚ⇕ఏᑟ⋡ࡢ ࢀࡿ᪂ࡋ࠸≀㉁ࢆ᥈⣴࣭〇ࡋ㸪ᐇ㦂ⓗᒁᅾ㠀 㛵㐃ࢆヲ⣽ㄪ㸪➨୍ཎ⌮ィ⟬ᐇ㦂⤖ᯝࡢ ㄪࣇ࢛ࣀࣥࡢᏑᅾࢆ☜ㄆࡋ㸪᱁Ꮚ⇕ఏᑟ⋡ࡢ 㛵㐃ࢆヲ⣽ㄪ㸪➨୍ཎ⌮ィ⟬ᐇ㦂⤖ᯝࡢ RT4X12 ࡇࢆ┠ⓗࡋࡓ㸬 ẚ㍑ࡼࡾ㸪᱁Ꮚ⇕ఏᑟ⋡ࡢపῶᶵᵓࢆゎ᫂ࡍࡿ ࣥẚ⇕ࡢᏑᅾࡶ㸪ࣛࢵࢺࣜࣥࢢࡢᐇ㦂ⓗドᣐ ࣥࢢࡢᏑᅾࢆ♧၀ࡋ࡚࠸ࡿ㸬ࡲࡓ㸪ࣥࢩࣗࢱ ⪃࠼ࡽࢀ࡚࠸ࡿ㸬ሸࢫࢡࢵࢸࣝࢲࢺྜ≀ ࣥẚ⇕ࡢᏑᅾࡶ㸪ࣛࢵࢺࣜࣥࢢࡢᐇ㦂ⓗドᣐ 4 T R T R ࠥ1100Υ࡛࠶ࡿ㸬 -4-4- － 4 － ࢝ࢦ≧ᕼᅵ㢮ྜ≀࠾ࡅࡿࣛࢵࢺࣜࣥࢢຠᯝࡼࡿ⇕ఏᑟ⋡పῶᶵᵓࡢゎ᫂ ࢝ࢦ≧ᕼᅵ㢮ྜ≀࠾ࡅࡿࣛࢵࢺࣜࣥࢢຠᯝࡼࡿ⇕ఏᑟ⋡పῶᶵᵓࡢゎ᫂ 3.2 ⤖ᬗᵓ㐀ゎᯒ 4.2 ࣛࢵࢺࣜࣥࢢࢆᐇ㦂ⓗ☜ㄆ ヨᩱࡢྠᐃࡣ‴᭤ IP X ⥺ᅇᢡ⨨ࢆ⏝ࡋ㸪 3.2 ⤖ᬗᵓ㐀ゎᯒ KD ⥺ࢆ⏝࠸ࡓ⢊ᮎ IP X ⥺ᅇᢡἲࡼࡾ⾜ࡗࡓ㸬 Coヨᩱࡢྠᐃࡣ‴᭤ X ⥺ᅇᢡ⨨ࢆ⏝ࡋ㸪 4.2 ᪂≀㉁ GdFe4As12 ࢆྵࡴከࡃࡢሸࢫࢡࢵࢸࣝ ࣛࢵࢺࣜࣥࢢࢆᐇ㦂ⓗ☜ㄆ X ⥺ࢆ⏝ࡋࡓ⢊ᮎ X ⥺ᅇ ࢲࢺྜ≀ࡢᨺᑕග ᪂≀㉁ GdFe As ࢆྵࡴከࡃࡢሸࢫࢡࢵࢸࣝ ᮎ X ⥺ᅇᢡᐇ㦂ࢹ࣮ࢱࢆ⏝࠸㸪࣮ࣜࢺ࣋ࣝࢺἲ BL10XU ࠾࠸࡚ᨺᑕග X ⥺ࢆ⏝ࡋ࡚⾜ࡗࡓ⢊ ࡼࡾᵓ㐀Ỵᐃࢆ⾜ࡗࡓ㸬㧗ᅽୗ࠾ࡅࡿ⢊ᮎ X⥺ ᮎ X ⥺ᅇᢡᐇ㦂ࢹ࣮ࢱࢆ⏝࠸㸪࣮ࣜࢺ࣋ࣝࢺἲ (3)㸬 ⇕ືࣃ࣓࣮ࣛࢱࢆồࡵࡓ ᐃࢆ⾜ࡗࡓྜ≀ 㐀ࣃ࣓࣮ࣛࢱ㸦X ཎᏊࡢᗙᶆ㸪 ཎᏊ㛫㊥㞳㸪 ⤖ྜゅ㸧㸪 ࡢ୰࡛㸪GdFe ཎᏊࡢసࡿ࢝ࢦ 4As12 ࡢ Gd ཎᏊ㸦As (3) ⇕ືࣃ࣓࣮ࣛࢱࢆồࡵࡓ 㸬 ᐃࢆ⾜ࡗࡓྜ≀ 4 ⢭ 㐀 ゎ ᯒ ࡣ 㸪 SPring-8 ࡢ ࣅ ࣮ ࣒ ࣛ ࣥ CoᐦKᵓ D ⥺ࢆ⏝࠸ࡓ⢊ᮎ X ⥺ᅇᢡἲࡼࡾ⾜ࡗࡓ㸬 BL10XU X ⥺ࢆ⏝ࡋ࡚⾜ࡗࡓ⢊ ⢭ ᐦ ᵓ 㐀࠾࠸࡚ᨺᑕග ゎ ᯒ ࡣ 㸪 SPring-8 ࡢࣅ࣮࣒ࣛࣥ 12 ᢡᐇ㦂ࢆ⾜࠸㸪࣮ࣜࢺ࣋ࣝࢺゎᯒࡼࡾ㸪⤖ᬗᵓ ࢲࢺྜ≀ࡢᨺᑕග X ⥺ࢆ⏝ࡋࡓ⢊ᮎ X ⥺ᅇ 㐀ࣃ࣓࣮ࣛࢱ 㸦X ཎᏊࡢᗙᶆ㸪ཎᏊ㛫㊥㞳㸪⤖ྜゅ㸧㸪 ᢡᐇ㦂ࢆ⾜࠸㸪࣮ࣜࢺ࣋ࣝࢺゎᯒࡼࡾ㸪⤖ᬗᵓ ᅇᢡᐇ㦂ࡣ㸪㧗࢚ࢿࣝࢠ࣮ຍ㏿ჾ◊✲ᶵᵓ(KEK) ࡼࡾᵓ㐀Ỵᐃࢆ⾜ࡗࡓ㸬㧗ᅽୗ࠾ࡅࡿ⢊ᮎ X⥺ ᨺ ᑕ ග ⛉ Ꮫ ◊ ✲ ࢭ ࣥ ࢱ ࣮ (PF) ࡢ ࣅ ࣮ ࣒ ࣛ ࣥ ᅇᢡᐇ㦂ࡣ㸪㧗࢚ࢿࣝࢠ࣮ຍ㏿ჾ◊✲ᶵᵓ(KEK) BL18C X࣮ ⥺ࢆ⏝ࡋ࡚⾜ࡗࡓ㸬㧗 ᨺ ᑕ ග࠾࠸࡚ᨺᑕග ⛉Ꮫ◊✲ࢭࣥࢱ (PF) ࡢ ࣅ ࣮ ࣒ ࣛ ࣥ ᵓ㐀ࡢ୰⨨ࡋ㸪ࢤࢫࢺཎᏊࡤࢀࡿ㸧ࡢ⇕ ࡢ୰࡛㸪GdFe4As12 ࡢ Gd ཎᏊ㸦As ཎᏊࡢసࡿ࢝ࢦ ືࣃ࣓࣮ࣛࢱࡀ᭱ࡶࡁ࡞್ࢆ♧ࡋ㸪㢧ⴭ࡞ࣛ ᵓ㐀ࡢ୰⨨ࡋ㸪ࢤࢫࢺཎᏊࡤࢀࡿ㸧ࡢ⇕ ࢵࢺࣜࣥࢢຠᯝࡀᮇᚅ࡛ࡁࡿ㸬GdFe 4As12 ࡣᖖᅽ࡛ ືࣃ࣓࣮ࣛࢱࡀ᭱ࡶࡁ࡞್ࢆ♧ࡋ㸪㢧ⴭ࡞ࣛ ࡢྜᡂሗ࿌ࡀ࡞ࡃ㸪㧗ᅽୗ࡛ࡢࡳྜᡂྍ⬟࡞≀㉁ ࢵࢺࣜࣥࢢຠᯝࡀᮇᚅ࡛ࡁࡿ㸬GdFe As ࡣᖖᅽ࡛ ᅽⓎ⏕⨨ࡋ࡚ࢲࣖࣔࣥࢻࣥࣅࣝࢭࣝࢆ⏝ BL18C ࠾࠸࡚ᨺᑕග X ⥺ࢆ⏝ࡋ࡚⾜ࡗࡓ㸬㧗 ࠸ࡓ㸬 ᅽⓎ⏕⨨ࡋ࡚ࢲࣖࣔࣥࢻࣥࣅࣝࢭࣝࢆ⏝ 4 12 ࡛࠶ࡾ㸪‽Ᏻᐃ≧ែࡢ㧗ᅽ┦ࡀࢡ࢚ࣥࢳࡉࢀ࡚࠸ ࡢྜᡂሗ࿌ࡀ࡞ࡃ㸪㧗ᅽୗ࡛ࡢࡳྜᡂྍ⬟࡞≀㉁ ࡿྍ⬟ᛶࡀ࠶ࡿ㸬㧗ᅽྜᡂࡼࡾ㸪Gd ࡼࡾࡉࡽ ࡛࠶ࡾ㸪‽Ᏻᐃ≧ែࡢ㧗ᅽ┦ࡀࢡ࢚ࣥࢳࡉࢀ࡚࠸ ࠸ࡓ㸬 3.3 ≀ᛶホ౯ 㔜࠸㔜ᕼᅵ㢮ඖ⣲ࢆྵࡴሸࢫࢡࢵࢸࣝࢲࢺ ࡿྍ⬟ᛶࡀ࠶ࡿ㸬㧗ᅽྜᡂࡼࡾ㸪Gd ࡼࡾࡉࡽ ྜ≀ࡀྜᡂ࡛ࡁࢀࡤ㸪ࡉࡽ㢧ⴭ࡞ࣛࢵࢺࣜࣥࢢ 㔜࠸㔜ᕼᅵ㢮ඖ⣲ࢆྵࡴሸࢫࢡࢵࢸࣝࢲࢺ 3.3 ᚓࡽࢀࡓヨᩱࡢ㟁Ẽᢠ㸪ẚ⇕㸪ࢮ࣮࣋ࢵࢡಀ ≀ᛶホ౯ ᩘ㸪⇕ఏᑟ⋡ࡢ ᐃࡣ≀⌮≉ᛶ ᐃ⨨ PPMS ᚓࡽࢀࡓヨᩱࡢ㟁Ẽᢠ㸪ẚ⇕㸪ࢮ࣮࣋ࢵࢡಀ ຠᯝࡀᮇᚅ࡛ࡁࡿ㸬 ྜ≀ࡀྜᡂ࡛ࡁࢀࡤ㸪ࡉࡽ㢧ⴭ࡞ࣛࢵࢺࣜࣥࢢ ᚓࡽࢀࡓ᪂≀㉁㛵ࡋ࡚㸪⤖ᬗᵓ㐀ࡢᅽຊ౫Ꮡ ຠᯝࡀᮇᚅ࡛ࡁࡿ㸬 (Quantum Design ♫〇)ࢆ⏝ࡋ㸪㟁Ẽᢠ ᐃࡣ ᩘ㸪⇕ఏᑟ⋡ࡢ ᐃࡣ≀⌮≉ᛶ ᐃ⨨ PPMS ┤ὶ 4 ➃Ꮚἲ㸪ẚ⇕ࡣ⦆ἲ㸪ࢮ࣮࣋ࢵࢡಀᩘ㸪 (Quantum Design ♫〇)ࢆ⏝ࡋ㸪㟁Ẽᢠ ᐃࡣ ᛶࡘ࠸࡚ࡶ⣔⤫ⓗ◊✲ࡋࡓ㸬㧗ᅽୗ࠾ࡅࡿ ᚓࡽࢀࡓ᪂≀㉁㛵ࡋ࡚㸪⤖ᬗᵓ㐀ࡢᅽຊ౫Ꮡ ⢊ᮎ X ⥺ᅇᢡᐇ㦂ࢆ⾜࠸㸪10GPa ࡲ࡛ࡢᅽຊ⠊ᅖ ᛶࡘ࠸࡚ࡶ⣔⤫ⓗ◊✲ࡋࡓ㸬㧗ᅽୗ࠾ࡅࡿ ⇕ఏᑟ⋡ࡢ ᐃࡣᐃᖖἲࡼࡾ⾜ࡗࡓ㸬 ┤ὶ 4 ➃Ꮚἲ㸪ẚ⇕ࡣ⦆ἲ㸪ࢮ࣮࣋ࢵࢡಀᩘ㸪 ⇕ఏᑟ⋡ࡢ ᐃࡣᐃᖖἲࡼࡾ⾜ࡗࡓ㸬 3.4 ศᏊືຊᏛ(MD)ࢩ࣑࣮ࣗࣞࢩࣙࣥ ࡛ࡣ㸪⤖ᬗᵓ㐀ࡣᏳᐃࡋ࡚࠾ࡾ㸪ᵓ㐀┦㌿⛣࡞ ⢊ᮎ X ⥺ᅇᢡᐇ㦂ࢆ⾜࠸㸪10GPa ࡲ࡛ࡢᅽຊ⠊ᅖ ࡢ␗ᖖࡣほ ࡉࢀ࡞ࡗࡓ㸬᱁Ꮚᐃᩘࡽࢭࣝయ ࡛ࡣ㸪⤖ᬗᵓ㐀ࡣᏳᐃࡋ࡚࠾ࡾ㸪ᵓ㐀┦㌿⛣࡞ 3.4 ሸࢫࢡࢵࢸࣝࢲࢺྜ≀࠾ࡅࡿ⤖ᬗ୰ࡢ ศᏊືຊᏛ(MD)ࢩ࣑࣮ࣗࣞࢩࣙࣥ ྛཎᏊࡢ⇕ືࢆㄪࡿࡇࢆ┠ⓗ㸪ྂⓗศ ሸࢫࢡࢵࢸࣝࢲࢺྜ≀࠾ࡅࡿ⤖ᬗ୰ࡢ ✚ ࢆィ⟬ࡋ㸪ࡑࡢᅽຊኚࡽయ✚ᙎᛶ⋡ࢆ ࡢ␗ᖖࡣほ ࡉࢀ࡞ࡗࡓ㸬᱁Ꮚᐃᩘࡽࢭࣝయ Birch-Murnaghan ✚ ࢆ ィ ⟬ ࡋ 㸪 ࡑ ࡢࡢ≧ែ᪉⛬ᘧࢆࣇࢵࢺࡉࡏ ᅽຊኚࡽయ✚ᙎᛶ⋡ࢆ ᏊືຊᏛ(MD)ࢩ࣑࣮ࣗࣞࢩࣙࣥࢆ⾜࠸㸪ࣃ࣮࣭࣡ ྛཎᏊࡢ⇕ືࢆㄪࡿࡇࢆ┠ⓗ㸪ྂⓗศ ࢫ࣌ࢡࢺࣝࡢゎᯒࢆ⾜ࡗࡓ㸬ࢩ࣑࣮ࣗࣞࢩࣙࣥࡢ ᏊືຊᏛ(MD)ࢩ࣑࣮ࣗࣞࢩࣙࣥࢆ⾜࠸㸪ࣃ࣮࣭࣡ ࡚⟬ฟࡋࡓ㸬య✚ᙎᛶ⋡ࡣ≀㉁ࡢ◳ࡉࢆ⾲ࡍ≀⌮ Birch-Murnaghan ࡢ≧ែ᪉⛬ᘧࢆࣇࢵࢺࡉࡏ 㔞࡛࠶ࡿࡀ㸪ྠᵝ◳ࡉࡢᣦᶆࡢ୍ࡘ࡛࠶ࡿࢹࣂ ࡚⟬ฟࡋࡓ㸬య✚ᙎᛶ⋡ࡣ≀㉁ࡢ◳ࡉࢆ⾲ࡍ≀⌮ ⤖ᯝࡣ㸪ᮏ≉㞟ࡢ⃝ཱྀࡽࡢグࢆཧ↷ࡋ࡚㡬ࡁࡓ ࢫ࣌ࢡࢺࣝࡢゎᯒࢆ⾜ࡗࡓ㸬ࢩ࣑࣮ࣗࣞࢩࣙࣥࡢ ࠸㸦9 ࣮࣌ࢪ㸧 㸬 ⤖ᯝࡣ㸪ᮏ≉㞟ࡢ⃝ཱྀࡽࡢグࢆཧ↷ࡋ࡚㡬ࡁࡓ ᗘࡢẚ㍑ࢆ⾜ࡗࡓ㸬ࡑࡢ⤖ᯝ㸪ሸࡉࢀࡿ 㔞࡛࠶ࡿࡀ㸪ྠᵝ◳ࡉࡢᣦᶆࡢ୍ࡘ࡛࠶ࡿࢹࣂ ࢜ࣥࡢ౯ᩘࡼࡾ␗࡞ࡿഴྥࡀぢࡽࢀ㸪ࣛࢵࢺ ᗘࡢẚ㍑ࢆ⾜ࡗࡓ㸬ࡑࡢ⤖ᯝ㸪ሸࡉࢀࡿ ࠸㸦9 ࣮࣌ࢪ㸧 㸬 ࣜࣥࢢຠᯝࡢ㛵㐃ࡀ♧၀ࡉࢀࡿ㸬ࡇࡢࡼ࠺㸪 ࢜ࣥࡢ౯ᩘࡼࡾ␗࡞ࡿഴྥࡀぢࡽࢀ㸪ࣛࢵࢺ ᪂つࡢ As ⣔ྜ≀ࡢྜᡂࡼࡾ㸪P ⣔ Sb ⣔ࡢ ࣜࣥࢢຠᯝࡢ㛵㐃ࡀ♧၀ࡉࢀࡿ㸬ࡇࡢࡼ࠺㸪 4 ◊✲ᡂᯝ 4 ◊✲ᡂᯝ 4.1 ࢝ࢦ≧ᵓ㐀ࢆᣢࡘ᪂≀㉁᥈⣴ 㝽㛫ࢆᇙࡵࡿࡇࡀ࡛ࡁ⣔⤫ⓗ࡞◊✲ࡀྍ⬟࡞ ᪂つࡢ As ⣔ྜ≀ࡢྜᡂࡼࡾ㸪P ⣔ Sb ⣔ࡢ ࡗࡓ㸬 㝽㛫ࢆᇙࡵࡿࡇࡀ࡛ࡁ⣔⤫ⓗ࡞◊✲ࡀྍ⬟࡞ 4.1 ࡇࢀࡲ࡛ᖖᅽୗࡢࣇࣛࢵࢡࢫἲ࡛ࡣྜᡂ࡛ࡁ࡞ ࢝ࢦ≧ᵓ㐀ࢆᣢࡘ᪂≀㉁᥈⣴ ࡗࡓ As ⣔ሸࢫࢡࢵࢸࣝࢲࢺྜ≀ࢆ㧗 㧗 ࡇࢀࡲ࡛ᖖᅽୗࡢࣇࣛࢵࢡࢫἲ࡛ࡣྜᡂ࡛ࡁ࡞ ࡗࡓ㸬 ᅽྜᡂἲࡼࡾྜᡂ࡛ࡁࡿࡇࢆぢฟࡋ㸪ࣝ࢝ ࡗࡓ As ⣔ሸࢫࢡࢵࢸࣝࢲࢺྜ≀ࢆ㧗 㧗 ࣜᅵ㢮㔠ᒓඖ⣲ࡢ Ba ࡸ㔜ᕼᅵ㢮ඖ⣲ࢆྵࡴ᪂つ ᅽྜᡂἲࡼࡾྜᡂ࡛ࡁࡿࡇࢆぢฟࡋ㸪ࣝ࢝ ሸࢫࢡࢵࢸࣝࢲࢺྜ≀ BaFe4As12㸪BaRu4As12㸪 ࣜᅵ㢮㔠ᒓඖ⣲ࡢ Ba ࡸ㔜ᕼᅵ㢮ඖ⣲ࢆྵࡴ᪂つ (2) ࡞ࡢྜᡂ BaOs As 㸪GdFe As 㸪TbFe As 4 12 4 12 4 12 ሸࢫࢡࢵࢸࣝࢲࢺྜ≀ BaFe As 㸪BaRu As 㸪 4 12 4 12 ᡂຌࡋࡓ㸬ࡲࡓ㸪᪂࢝ࢦ≧≀㉁࡛࠶ࡿ CeFe2Al10 ࡢ BaOs4As12 㸪GdFe4As12 㸪TbFe4As12(2) ࡞ࡢྜᡂ 㧗ᅽྜᡂᡂຌࡋࡓ㸬ヲ⣽ࡣᮏ≉㞟ࡢᕝᮧࡽࡢグ ᡂຌࡋࡓ㸬ࡲࡓ㸪᪂࢝ࢦ≧≀㉁࡛࠶ࡿ CeFe Al ࡢ 2 10 ࢆཧ↷ࡋ࡚㡬ࡁࡓ࠸㸦13 ࣮࣌ࢪ㸧㸬ࡲࡓ㸪Ce ࡸ 㧗ᅽྜᡂᡂຌࡋࡓ㸬ヲ⣽ࡣᮏ≉㞟ࡢᕝᮧࡽࡢグ La ࢆᡂศࡍࡿΰྜᕼᅵ 㸦࣑ࢵࢩ࣓ࣗࢱࣝ㸪 ࢆཧ↷ࡋ࡚㡬ࡁࡓ࠸㸦13 ࣮࣌ࢪ㸧㸬ࡲࡓ㸪CeMm ࡸ ⾲グࡉࢀࡿ㸧ࢆྵࡴ᪂つሸࢫࢡࢵࢸࣝࢲࢺ La ࢆᡂศࡍࡿΰྜᕼᅵ㸦࣑ࢵࢩ࣓ࣗࢱࣝ㸪Mm ྜ≀ MmxCo4Sb12, MmFe4Sb12, MmFe3CoSb12 ࡞ ⾲グࡉࢀࡿ㸧ࢆྵࡴ᪂つሸࢫࢡࢵࢸࣝࢲࢺ ᅗ2Ybࡢ㎸ࡳ್x ᑐࡍࡿYbxCo4Sb12 ࡢ᱁Ꮚᐃᩘaࡢኚ ᅗ2Ybࡢ㎸ࡳ್x ᑐࡍࡿYb Co Sb ࢆ ྜ ᡂMm ࡍ ࡿCo ࡇ Sb , ᡂ ຌࡋ㸪ᐇ⏝ࡉࢀ࡚࠸ࡿ ྜ≀ x 4 12 MmFe4Sb12, MmFe3CoSb12 ࡞ CoSb ྠ⛬ᗘࡢᛶ⬟ࢆ᭷ࡍࡿࡇࡀ☜ㄆ࡛ CeFe 12 ࢆ ྜ3ᡂ ࡍ ࡿ ࡇᡂຌࡋ㸪ᐇ⏝ࡉࢀ࡚࠸ࡿ x ࡁࡓ㸬 CeFe3CoSb12 ྠ⛬ᗘࡢᛶ⬟ࢆ᭷ࡍࡿࡇࡀ☜ㄆ࡛ ࡁࡓ㸬 ࡢ᱁Ꮚᐃᩘaࡢኚ -5-5- － 5 － 4 12 㛵᰿ࡕࡦࢁ㸪ᕝᮧᖾ⿱㸪Ṋ⏣ᆂ⏕㸪⃝ཱྀ┤ဢ㸪㓇ᙲ୰᰿ⱥ❶ 㛵᰿ࡕࡦࢁ㸪ᕝᮧᖾ⿱㸪Ṋ⏣ᆂ⏕㸪⃝ཱྀ┤ဢ㸪㓇ᙲ୰᰿ⱥ❶ 4.3 Yb ሸࡼࡿ᱁Ꮚ⇕ఏᑟ⋡ࡢపῶ 㠀ሸࢫࢡࢵࢸࣝࢲࢺྜ≀ CoSb3 ᕼᅵ㢮 4.3 Yb ሸࡼࡿ᱁Ꮚ⇕ఏᑟ⋡ࡢపῶ ඖ⣲ࡢ Yb ࢆ㒊ศⓗሸࡉࡏࡓ YbxCo4Sb12 ࡣ㧗࠸ 㠀ሸࢫࢡࢵࢸࣝࢲࢺྜ≀ CoSb3 ᕼᅵ㢮 ᛶ⬟ᣦᩘࢆ♧ࡍ n ᆺࡢ⇕㟁ᮦᩱࡋ࡚▱ࡽࢀ࡚࠸ ඖ⣲ࡢ Yb ࢆ㒊ศⓗሸࡉࡏࡓ YbxCo4Sb12 ࡣ㧗࠸ ࡿࡀ㸪ᖖᅽ࡛ࡢྜᡂ࡛ࡣ㸪Yb ࡢሸ⋡ࡣ 20㸣௨ୗ ᛶ⬟ᣦᩘࢆ♧ࡍ n ᆺࡢ⇕㟁ᮦᩱࡋ࡚▱ࡽࢀ࡚࠸ ␃ࡲࡿ(4)㸬ᮏ◊✲࡛ࡣ㧗 㧗ᅽྜᡂἲࡼࡾ㸪㧗 ࡿࡀ㸪ᖖᅽ࡛ࡢྜᡂ࡛ࡣ㸪Yb ࡢሸ⋡ࡣ 20㸣௨ୗ ࠸ሸ⋡ࡢ YbxCo4Sb12 ࡢྜᡂࢆヨࡳ㸪Yb ࡢሸ㔞 ␃ࡲࡿ(4)㸬ᮏ◊✲࡛ࡣ㧗 㧗ᅽྜᡂἲࡼࡾ㸪 㧗 ᑐࡍࡿ᱁Ꮚ⇕ఏᑟ⋡࡞⇕㟁≉ᛶࡢኚࢆㄪ ࠸ሸ⋡ࡢ YbxCo4Sb12 ࡢྜᡂࢆヨࡳ㸪Yb ࡢሸ㔞 ࡓ㸬ᅗ 2 㸪Yb ࡢ㎸ࡳ್ x ᑐࡍࡿ 2GPa ࡛ ᑐࡍࡿ᱁Ꮚ⇕ఏᑟ⋡࡞⇕㟁≉ᛶࡢኚࢆㄪ ྜᡂࡋࡓ YbxCo4Sb12 ࡢ᱁Ꮚᐃᩘ a ࡢኚࢆ♧ࡍ㸬 ࡓ㸬ᅗ 2 㸪Yb ࡢ㎸ࡳ್ x ᑐࡍࡿ 2GPa ࡛ x ࡢቑຍࡶ᱁Ꮚᐃᩘ a ࡣቑࡍࡿࡀ㸪x=0.6 ྜᡂࡋࡓ YbxCo4Sb12 ࡢ᱁Ꮚᐃᩘ a ࡢኚࢆ♧ࡍ㸬 ௨ୖ࡛ࡣቑࡣぢࡽࢀ࡞ࡃ࡞ࡿ㸬ࡇࡢࡇࡽ㸪 x ࡢቑຍࡶ᱁Ꮚᐃᩘ a ࡣቑࡍࡿࡀ㸪x=0.6 2GPa ࡛ࡢྜᡂ࡛ࡣ㸪CoSb3 ࡢ Yb ࡢሸ⋡ࡣ ௨ୖ࡛ࡣቑࡣぢࡽࢀ࡞ࡃ࡞ࡿ㸬ࡇࡢࡇࡽ㸪 60㸣ࡀ㝈⏺⪃࠼ࡽࢀࡿࡀ㸪㧗ᅽྜᡂἲࢆ⏝࠸ࡿ 2GPa ࡛ࡢྜᡂ࡛ࡣ㸪CoSb3 ࡢ Yb ࡢሸ⋡ࡣ ࡇ࡛㸪㧗࠸ሸ⋡ࡢ YbxCo4Sb12 ࡢྜᡂࡀྍ⬟࡛ 60㸣ࡀ㝈⏺⪃࠼ࡽࢀࡿࡀ㸪㧗ᅽྜᡂἲࢆ⏝࠸ࡿ ࠶ࡿࡇࡀᐇド࡛ࡁࡓ㸬ࡉࡽ㸪Yb ࡢሸ⋡ࡢቑ ࡇ࡛㸪㧗࠸ሸ⋡ࡢ YbxCo4Sb12 ࡢྜᡂࡀྍ⬟࡛ ຍࡶ࡞࠸ YbxCo4Sb12 ࡢ᱁Ꮚ⇕ఏᑟ⋡(NL)ࡣ ࠶ࡿࡇࡀᐇド࡛ࡁࡓ㸬ࡉࡽ㸪Yb ࡢሸ⋡ࡢቑ ࡁࡃῶᑡࡋࡓ㸦ᅗ 3㸧㸬ࡇࢀࡣ㸪Yb ཎᏊࡀ㢧ⴭ࡞ࣛ ຍࡶ࡞࠸ YbxCo4Sb12 ࡢ᱁Ꮚ⇕ఏᑟ⋡(NL)ࡣ ࢵࢺࣜࣥࢢຠᯝࢆ♧ࡍࡇࢆᙉࡃ♧၀ࡍࡿ⤖ᯝ࡛ ࡁࡃῶᑡࡋࡓ㸦ᅗ 3㸧㸬ࡇࢀࡣ㸪Yb ཎᏊࡀ㢧ⴭ࡞ࣛ ࠶ࡿ㸬 ࢵࢺࣜࣥࢢຠᯝࢆ♧ࡍࡇࢆᙉࡃ♧၀ࡍࡿ⤖ᯝ࡛ ᅗ3YbxCo4Sb12ࡢ᱁Ꮚ⇕ఏᑟ⋡NLࡢ ᗘኚ ᅗ3YbxCo4Sb12ࡢ᱁Ꮚ⇕ఏᑟ⋡NLࡢ ᗘኚ ࢆᙧᡂࡋ࡚࠸ࡿ୍㒊ࡢ Sb ཎᏊࡀ࢝ࢦෆ㒊ࡢ✵㝽 ᢲࡋ ㎸ࡵࡽࢀ ࡓ㸪͆ ⮬ᕫሸ ᛂ͇ࣔ ࢹࣝ㸦ڧ ࢆᙧᡂࡋ࡚࠸ࡿ୍㒊ࡢ Sb ཎᏊࡀ࢝ࢦෆ㒊ࡢ✵㝽 Co4Sb12→SbxCo4Sb12-x㸧࡛ㄝ࡛᫂ࡁࡿࡇࢆᥦၐࡋ ᢲࡋ ㎸ࡵࡽࢀ ࡓ㸪͆ ⮬ᕫሸ ᛂ͇ࣔ ࢹࣝ㸦ڧ ࡚࠸ࡿ㸬ᐇ㝿ᥦၐࡉࢀ࡚࠸ࡿࣔࢹࣝࡢ⌧㇟ࡀ㉳ Co4Sb12→SbxCo4Sb12-x㸧࡛ㄝ࡛᫂ࡁࡿࡇࢆᥦၐࡋ ࡇࡗ࡚࠸ࡿ௬ᐃࡍࡿ㸪࢝ࢦෆ㒊ሸࡉࢀࡓ ࡚࠸ࡿ㸬ᐇ㝿ᥦၐࡉࢀ࡚࠸ࡿࣔࢹࣝࡢ⌧㇟ࡀ㉳ Sb ࡀ㸪YbxCo4Sb12 ࡞ࡢሸࢫࢡࢵࢸࣝࢲࢺ ࡇࡗ࡚࠸ࡿ௬ᐃࡍࡿ㸪࢝ࢦෆ㒊ሸࡉࢀࡓ ྜ≀࡛ぢࡽࢀ࡚࠸ࡿࡼ࠺࡞㸪ࣛࢵࢺࣜࣥࢢຠᯝࢆ Sb ࡀ㸪YbxCo4Sb12 ࡞ࡢሸࢫࢡࢵࢸࣝࢲࢺ ㉳ࡇࡍྍ⬟ᛶࡀ࠶ࡾ㸪᱁Ꮚ⇕ఏᑟ⋡NL ࢆపῶࡉࡏ ྜ≀࡛ぢࡽࢀ࡚࠸ࡿࡼ࠺࡞㸪ࣛࢵࢺࣜࣥࢢຠᯝࢆ ࡿࡇࡀᮇᚅ࡛ࡁ㸪ᛶ⬟ᣦᩘ Z ࢆྥୖࡉࡏࡿ⪃ ㉳ࡇࡍྍ⬟ᛶࡀ࠶ࡾ㸪᱁Ꮚ⇕ఏᑟ⋡NL ࢆపῶࡉࡏ ࠼ࡽࢀࡿ㸬ࡋࡋ㸪⣙ 40GPa ࡢ㧗࠸ᅽຊୗ࡛㉳ࡇ ࡿࡇࡀᮇᚅ࡛ࡁ㸪ᛶ⬟ᣦᩘ Z ࢆྥୖࡉࡏࡿ⪃ ࡿ⌧㇟࡛࠶ࡿࡓࡵ㸪ᐇ㦂ࡢᅔ㞴ࡉࡽ㸪ࢇ ࠼ࡽࢀࡿ㸬ࡋࡋ㸪⣙ 40GPa ࡢ㧗࠸ᅽຊୗ࡛㉳ࡇ ヲ⣽࡞◊✲ࡣࡉࢀ࡚࠸࡞ࡗࡓ㸬ᡃࠎࡣ㸪ᨺᑕග X ࡿ⌧㇟࡛࠶ࡿࡓࡵ㸪ᐇ㦂ࡢᅔ㞴ࡉࡽ㸪ࢇ ⥺ࢆ⏝࠸ࡓ㧗⢭ᗘࡢᐇ㦂ࢆ⾜࠸㸪⮬ᕫሸᛂࡢ ヲ⣽࡞◊✲ࡣࡉࢀ࡚࠸࡞ࡗࡓ㸬ᡃࠎࡣ㸪ᨺᑕග X ጇᙜᛶࢆ☜ㄆࡋࡓ(6)㸬ࡲࡓ㸪CoSb3 ྠࡌ⤖ᬗᵓ㐀 ⥺ࢆ⏝࠸ࡓ㧗⢭ᗘࡢᐇ㦂ࢆ⾜࠸㸪⮬ᕫሸᛂࡢ ࢆᣢࡘ RhSb3㸪IrSb 3㸪TAs3 㸦T=Co㸪Rh㸪Ir㸧࡛ࡶ (6)㸬ࡲࡓ㸪CoSb ጇᙜᛶࢆ☜ㄆࡋࡓ 3 ྠࡌ⤖ᬗᵓ㐀 ྠᵝࡢ⌧㇟ࡀ㉳ࡇࡿࡇࢆึࡵ࡚♧ࡋ㸪㠀ሸࢫ ࢆᣢࡘ RhSb3㸪IrSb3㸪TAs3㸦T=Co㸪Rh㸪Ir㸧࡛ࡶ ࢡࢵࢸࣝࢲࢺྜ≀ࡢ㧗ᅽୗ࠾ࡅࡿ⤖ᬗᵓ㐀 ྠᵝࡢ⌧㇟ࡀ㉳ࡇࡿࡇࢆึࡵ࡚♧ࡋ㸪㠀ሸࢫ ࡢᏳᐃᛶࡘ࠸࡚㸪⣔⤫ⓗホ౯ࡍࡿࡇࡀྍ ࢡࢵࢸࣝࢲࢺྜ≀ࡢ㧗ᅽୗ࠾ࡅࡿ⤖ᬗᵓ㐀 ⬟࡞ࡗࡓ㸬⮬ᕫሸᛂࡣᐊ ௨ୖࡢ ᗘ࡛ࡣ ࡢᏳᐃᛶࡘ࠸࡚㸪⣔⤫ⓗホ౯ࡍࡿࡇࡀྍ ࡼࡾప࠸ᅽຊ࡛㉳ࡇࡿࡇࡶ☜ㄆࡉࢀࡓ㸬 ⬟࡞ࡗࡓ㸬⮬ᕫሸᛂࡣᐊ ௨ୖࡢ ᗘ࡛ࡣ ࠶ࡿ㸬 4.4 㠀ሸࢫࢡࢵࢸࣝࢲࢺྜ≀ࡢ⮬ᕫሸ ᛂ 4.4 㠀ሸࢫࢡࢵࢸࣝࢲࢺྜ≀ࡢ⮬ᕫሸ ከࡃࡢ࢝ࢦ≧ྜ≀ࡣ㸪࢝ࢦෆ㒊ሸࡉࢀࡓ ᛂ ࢤࢫࢺཎᏊࡼࡗ࡚⤖ᬗᵓ㐀ࡀಖࡓࢀ࡚࠾ࡾ㸪ࢤ ከࡃࡢ࢝ࢦ≧ྜ≀ࡣ㸪࢝ࢦෆ㒊ሸࡉࢀࡓ ࢫࢺཎᏊࡀᢤࡅࡓᵓ㐀ࡣᏳᐃࡋ࡚Ꮡᅾࡋ࡞࠸㸬ࡋ ࢤࢫࢺཎᏊࡼࡗ࡚⤖ᬗᵓ㐀ࡀಖࡓࢀ࡚࠾ࡾ㸪ࢤ ࡋ㸪ࢫࢡࢵࢸࣝࢲࢺྜ≀ࡣ㸪࢝ࢦෆ㒊 ࢫࢺཎᏊࡀᢤࡅࡓᵓ㐀ࡣᏳᐃࡋ࡚Ꮡᅾࡋ࡞࠸㸬ࡋ ࢤࢫࢺཎᏊࡀᏑᅾࡋ࡞࠸㸪㠀ሸࢫࢡࢵࢸࣝࢲ ࡋ㸪ࢫࢡࢵࢸࣝࢲࢺྜ≀ࡣ㸪࢝ࢦෆ㒊 ࢺྜ≀ MX㸦ڧM (✵=ڧ㝽㸪M=Co, Rh, Ir, X=P, 3 4X12㸧 ࢤࢫࢺཎᏊࡀᏑᅾࡋ࡞࠸㸪㠀ሸࢫࢡࢵࢸࣝࢲ As, Sb)ࡀᏳᐃࡋ࡚Ꮡᅾࡍࡿ㸬ࣛࢵࢺࣜࣥࢢ◊✲ ࢺྜ≀ MX㸦ڧM (✵=ڧ㝽㸪M=Co, Rh, Ir, X=P, 3 4X12㸧 ࡣ㸪ࡑࡢ⯙ྎ࡞ࡿ࢝ࢦ≧ᵓ㐀ࡑࡢࡶࡢࡢᏳᐃᛶ As, Sb)ࡀᏳᐃࡋ࡚Ꮡᅾࡍࡿ㸬ࣛࢵࢺࣜࣥࢢ◊✲ ࢆㄪࡿࡇࡶ㔜せ࡛࠶ࡿ㸬㠀ሸࢫࢡࢵࢸࣝࢲ ࡣ㸪ࡑࡢ⯙ྎ࡞ࡿ࢝ࢦ≧ᵓ㐀ࡑࡢࡶࡢࡢᏳᐃᛶ ࢺྜ≀ࡣ㸪12 ಶࡢ X ཎᏊࡀ 20 㠃యࡢ࢝ࢦࢆ ࢆㄪࡿࡇࡶ㔜せ࡛࠶ࡿ㸬㠀ሸࢫࢡࢵࢸࣝࢲ ᙧᡂࡋ㸪ࡑࡢ୰ᚰࡣ✵㝽࡞ࡗ࡚࠸ࡿ㸦ᅗ 1(a)㸧㸬 ࢺྜ≀ࡣ㸪12 ಶࡢ X ཎᏊࡀ 20 㠃యࡢ࢝ࢦࢆ ࡇࡢ࢝ࢦෆ㒊ࡢ✵㝽ࡣ㸪YbxCo4Sb12 ࡞௦⾲ࡉࢀ ᙧᡂࡋ㸪ࡑࡢ୰ᚰࡣ✵㝽࡞ࡗ࡚࠸ࡿ㸦ᅗ 1(a)㸧㸬 ࡿࡼ࠺㸪୍ࡘࡢᕼᅵ㢮࢜ࣥࡀሸ࡛ࡁࡿ ࡇࡢ࢝ࢦෆ㒊ࡢ✵㝽ࡣ㸪YbxCo4Sb12 ࡞௦⾲ࡉࢀ ࡁࡃ㸪⤖ᬗᵓ㐀ෆࡁ࡞✵㝽ࢆ᭷ࡍࡿ⤖ᬗᵓ ࡿࡼ࠺㸪୍ࡘࡢᕼᅵ㢮࢜ࣥࡀሸ࡛ࡁࡿ 㐀࡞ࡗ࡚࠸ࡿ㸬ࡲࡓ㸪࢝ࢦࢆᙧᡂࡍࡿཎᏊ㛫㸦X-X ࡁࡃ㸪⤖ᬗᵓ㐀ෆࡁ࡞✵㝽ࢆ᭷ࡍࡿ⤖ᬗᵓ ཎᏊ㛫㸧ࡢᙉ࠸ඹ᭷⤖ྜࡢࡓࡵ㸪ࡇࢀࡲ࡛ࡣ㸪ཎ 㐀࡞ࡗ࡚࠸ࡿ㸬ࡲࡓ㸪࢝ࢦࢆᙧᡂࡍࡿཎᏊ㛫㸦X-X Ꮚᐦᗘࡢప࠸⤖ᬗᵓ㐀࡛࠶ࡿࡶࢃࡽࡎ㸪㠀 ཎᏊ㛫㸧ࡢᙉ࠸ඹ᭷⤖ྜࡢࡓࡵ㸪ࡇࢀࡲ࡛ࡣ㸪ཎ ᖖ㧗࠸ᅽຊࡲ࡛Ᏻᐃ࡞⤖ᬗᵓ㐀ࡀಖࡓࢀࡿࡇ Ꮚᐦᗘࡢప࠸⤖ᬗᵓ㐀࡛࠶ࡿࡶࢃࡽࡎ㸪㠀 ࡀሗ࿌ࡉࢀ࡚࠸ࡓ㸬ࡇࢁࡀ㸪᭱㏆ࡢ㧗ᅽୗ⢊ᮎ X ᖖ㧗࠸ᅽຊࡲ࡛Ᏻᐃ࡞⤖ᬗᵓ㐀ࡀಖࡓࢀࡿࡇ ⥺ᅇᢡᐇ㦂ࡽ㸪㠀ሸࢫࢡࢵࢸࣝࢲࢺྜ≀ ࡀሗ࿌ࡉࢀ࡚࠸ࡓ㸬ࡇࢁࡀ㸪᭱㏆ࡢ㧗ᅽୗ⢊ᮎ X CoSb3 ࡢᅽຊㄏ㉳ᵓ㐀ኚࡀሗ࿌ࡉࢀࡓ 㸦5㸧㸬ࡇࡢ ⥺ᅇᢡᐇ㦂ࡽ㸪㠀ሸࢫࢡࢵࢸࣝࢲࢺྜ≀ ㄽᩥ࡛ࡣ㸪ྍ㏫ⓗ࡞ᅽຊ㸫య✚᭤⥺ຍᅽᚋ CoSb3 ࡢᅽຊㄏ㉳ᵓ㐀ኚࡀሗ࿌ࡉࢀࡓ 㸦5㸧㸬ࡇࡢ ࢭࣝయ✚ࡀቑࡍࡿ␗ᖖࡀሗ࿌ࡉࢀ࡚࠾ࡾ㸪࢝ࢦ ㄽᩥ࡛ࡣ㸪ྍ㏫ⓗ࡞ᅽຊ㸫య✚᭤⥺ຍᅽᚋ ࢭࣝయ✚ࡀቑࡍࡿ␗ᖖࡀሗ࿌ࡉࢀ࡚࠾ࡾ㸪࢝ࢦ ࡼࡾప࠸ᅽຊ࡛㉳ࡇࡿࡇࡶ☜ㄆࡉࢀࡓ㸬 5 ࡲࡵ 5 ࡲࡵ ࢝ࢦ≧ᵓ㐀ࢆ᭷ࡍࡿᕼᅵ㢮ྜ≀ࡢ⇕㟁ኚᮦ ᩱࡢᛂ⏝ࢆ┠ᣦࡋࡓᇶ♏◊✲ࢆ⾜ࡗࡓ㸬ᆺ≀ ࢝ࢦ≧ᵓ㐀ࢆ᭷ࡍࡿᕼᅵ㢮ྜ≀ࡢ⇕㟁ኚᮦ ㉁ࡢྜᡂࡼࡾ㸪ࣛࢵࢺࣜࣥࢢ㉳ᅉࡍࡿ⪃࠼ ᩱࡢᛂ⏝ࢆ┠ᣦࡋࡓᇶ♏◊✲ࢆ⾜ࡗࡓ㸬ᆺ≀ ࡽࢀࡿ⌧㇟ࢆᐇ㦂ⓗ☜ㄆࡋ㸪᱁Ꮚ⇕ఏᑟ⋡ࡢప ㉁ࡢྜᡂࡼࡾ㸪ࣛࢵࢺࣜࣥࢢ㉳ᅉࡍࡿ⪃࠼ ῶ㛵ࡍࡿ᪂ࡓ࡞▱ぢࢆᚓࡓ㸬ࡲࡓ㸪㠀ሸࢫࢡ ࡽࢀࡿ⌧㇟ࢆᐇ㦂ⓗ☜ㄆࡋ㸪᱁Ꮚ⇕ఏᑟ⋡ࡢప ࢵࢸࣝࢲࢺྜ≀ࡢ⮬ᕫሸᛂࡣ㸪㧗 ᅽຊ ῶ㛵ࡍࡿ᪂ࡓ࡞▱ぢࢆᚓࡓ㸬ࡲࡓ㸪㠀ሸࢫࢡ ฎ⌮ࡼࡾ⇕㟁≉ᛶࢆྥୖࡉࡏࡿྍ⬟ᛶࢆ♧ࡋࡓ㸬 ࢵࢸࣝࢲࢺྜ≀ࡢ⮬ᕫሸᛂࡣ㸪㧗 ᅽຊ ฎ⌮ࡼࡾ⇕㟁≉ᛶࢆྥୖࡉࡏࡿྍ⬟ᛶࢆ♧ࡋࡓ㸬 -6-6- － 6 － ࢝ࢦ≧ᕼᅵ㢮ྜ≀࠾ࡅࡿࣛࢵࢺࣜࣥࢢຠᯝࡼࡿ⇕ఏᑟ⋡పῶᶵᵓࡢゎ᫂ ࢝ࢦ≧ᕼᅵ㢮ྜ≀࠾ࡅࡿࣛࢵࢺࣜࣥࢢຠᯝࡼࡿ⇕ఏᑟ⋡పῶᶵᵓࡢゎ᫂ Skutterudite Compound BaFe4As12 Prepared at High Pressure, J. 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Ser. 273 and Ir; X = As and Sb) under High Pressure, J. Phys. Soc. K. Takeda , K. Ito, J. Hayashi, C. Sekine, and T. Yagi, (2011) 012120 pages). Properties of New Filled Jpn. 81 (2012) 104604 (7 pages). Structural and(4Electrical K. Takeda, K. Ito, J. Hayashi, C. Sekine, and T. Yagi, Structural and Electrical Properties of New Filled ࡇࢀࡣḟୡ௦⇕㟁ኚᮦᩱ㛤Ⓨ᪂ࡓ࡞ᣦ㔪ࢆ ࠼ࡿࡶࡢ࡛࠶ࡿ⪃࠼ࡽࢀࡿ㸬 ࡇࢀࡣḟୡ௦⇕㟁ኚᮦᩱ㛤Ⓨ᪂ࡓ࡞ᣦ㔪ࢆ ࠼ࡿࡶࡢ࡛࠶ࡿ⪃࠼ࡽࢀࡿ㸬 (1) (1) (2) (2) (3) (3) -7-7- － 7 －
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