⺖㗴⇟ภ㧦2007A1924㧛૶↪ࡆ࡯ࡓ࡜ࠗࡦ㧦BL02B2‫ޟ‬GeTe-Bi2Te3ᡆੑర♽ൻว‛: Ge1Bi4Te7ߩ⚿᥏᭴ㅧ‫ޠ‬᧻ ᳗ ೑ ਯ1) (0005185)‫ ఽޔ‬ፉ ℂ ᕺ2)‫ޔ‬ጊ ↰ ᣹2) (0006748)

ᧁ ⥵ ᒄ ৻3) (0013757)‫ޔ‬ਭ ଻ ↰ ૫ ၮ4) (0001269)

1) ࢃ᧻ਅ࠹ࠢࡁ࡝ࠨ࡯࠴ ⭯⤑ಽᨆࠣ࡞࡯ࡊ
‫ޥ‬570-8501ᄢ㒋ᐭ቞ญᏒ౎㔕ਛ↸ਃৼ⋡৻⇟৻ภ㧔matsunaga.toshiyuki@jp.panasonic.com㧕
2) ᧻ਅ㔚ེ↥ᬺࢃ 㧭㨂ࠦࠕᛛⴚ㐿⊒࠮ࡦ࠲࡯‫ޔ‬3) ᄢ㒋ᐭ┙ᄢቇ ✚วᢎ⢒⎇ⓥᯏ᭴4) ᄢ㒋ᐭ┙ᄢቇᄢቇ㒮 ℂቇ♽⎇ⓥ⑼ ‛ℂ⑼ቇኾ᡹



DVD-RAM ߿ Blu-ray disc ߦઍ⴫ߐࠇࠆᄢኈ㊂㜞ㅦ⋧ᄌൻశ⸥㍳ᇦ૕ߣߒߡ‫ޔ‬GeTe-Sb2Te3
ᡆੑర♽ൻว‛߇ᦨ߽ఝࠇߚ㜞ㅦ⋧ᄌൻ․ᕈ‫․࡞ࡃࠗࠞ࡯ࠕޔ‬ᕈࠍ␜ߒ‫ޔ‬ᄙߊߩᏒ⽼࠺ࠖࠬࠢߦᄙ↪ߐࠇߡ޿ࠆ[1]‫ߩߎޕ‬ᡆੑర♽ൻว‛ߪ‫ޔ‬ᾲᐔⴧ⁁ᘒߢߪ‫ߣ⋧ࠬࠟࡠࡕࡎޔ‬๭߫ࠇࠆ᭽‫ߩޘ‬㊄ዻ㑆ൻว‛㧔቟ቯ⋧㧕ࠍᒻᚑߔࠆߎߣ߇⍮ࠄࠇߡ޿ࠆ‫৻ޕ‬ᣇߎߩ♽ߪ‫ޔ‬⍍㑆⊛ߥ࡟࡯ࠩ࡯ᾖ኿ߦࠃࠅ‫ޔ‬GeTe ߆ࠄ‫ޔ‬ዋߥߊߣ߽ GeSb4Te7 ߹ߢߩᐢ޿⚵ᚑ㗔ၞߦ߅޿ߡ‫ޔ‬NaCl ဳ᭴ㅧࠍᜬߟḰ቟ቯ⋧ߦ⚿᥏ൻߔࠆ[2]‫ޕ‬ᚒ‫ޔߪޘ‬SPring-8 ࠍ೑↪ߒߚߎߎ 5㨪6 ᐕ㑆ߩ⎇ⓥࠍㅢߒ‫ޔࠬࠔࡈ࡞ࡕࠕޔ‬Ḱ቟ቯ⋧‫ޔ‬቟ቯ⋧ߩ᭴ㅧ߿㔚ሶ⁁ᘒࠍ⹦⚦ߦᬌ⸛ߒ‫ޔ‬㜞ㅦ⋧ᄌൻࡔࠞ࠾࠭ࡓࠍ⸃᣿ߒߡ߈ߚ‫ߩߎޕ‬ൻว‛ߪ‫ߩߎޔ‬Ḱ቟ቯ⋧߇ሽ࿷ߔࠆ߆ࠄߎߘ‫ࡕࠕޔ‬࡞ࡈࠔࠬ㧔⸥㍳⁁ᘒ㧕߆ࠄ⚿᥏㧔ᶖ෰⁁ᘒ㧕߳ߩ㜞ㅦ⋧ᄌൻ߇น⢻ߣߥߞߡ޿ࠆߩߢ޽ࠆ[3]‫ޕ‬Ḱ቟ቯ⋧ߪ‫ޔ‬Sb2Te3 ߩ⚵ᚑᲧ߇ᄢ߈ߊߥࠆ߶ߤ‫⚿ޔ‬᥏ൻㅦᐲߪ਄߇ࠆ㧔㜞ㅦ⋧ᄌൻ߇น⢻ߣߥࠆ㧕߇‫ޔ‬ㅒߦ᭴ㅧߪਇ቟ቯߣߥࠅ‫ޔ‬⍴ᤨ㑆ߢ቟ቯ⋧ߦ᭴ㅧ⋧ォ⒖ߔࠆ‫࡯ࠩ࡯࡟ޕ‬ᾖ኿ߦ
ࠃߞߡ NaCl ဳḰ቟ቯ⋧߇ᓧࠄࠇࠆߩߪ‫ޔ‬GeSb4Te7 ⚵ᚑ߹ߢߢ޽ࠆ[2]‫⃻ޕ‬࿷‫ޔ‬ᚒ‫ࡕࠕޔߪޘ‬࡞ࡈࠔࠬ‫ޔ‬Ḱ቟ቯ⋧ߩߺߥࠄߕ‫ޔ‬቟ቯ⋧ߩ᭴ㅧ߽‫⺞ߦ⚦⹦ޔ‬ᩏ‫ޔ‬ᬌ⸛ߔࠆߎߣߦࠃࠅ‫ߎޔ‬ߩൻว‛ߩో૕௝ࠍ⸃᣿ߒ‫․ࠅࠃޔ‬ᕈߦఝࠇߚ᧚ᢱࠍ㐿⊒ߔࠆߚ߼ߩᜰ㊎ࠍᓧࠃ߁ߣദജߒߡ޿ࠆ‫ޕ‬GeTe-Sb2Te3 ᡆੑర♽ൻว‛߽฽߼ߡ‫ޔ‬Φ-Χ-Ψᣖర⚛ߦࠃߞߡ᭴ᚑߐࠇࠆࠞ࡞ࠦࠥ࠽ࠗ࠼ᡆੑర♽ൻว‛㧔GeTe-Bi2Te3 ♽‫ޔ‬SnTe-Bi2Te3 ♽‫ޔ‬PbTe-Sb2Te3 ♽‫ޔ‬PbTe-Bi2Te3♽ߥߤ㧕ߪ‫⋧ޔ‬ᄌൻశ⸥㍳᧚ᢱߩߺߥࠄߕ‫ޔ‬ਇើ⊒ᕈߩ㔚᳇ࡔࡕ࡝࡯߿ᾲ㔚ᄌ឵᧚ᢱ߳ߩᔕ↪߽⠨߃ࠄࠇߡ߅ࠅ[4]‫᧚ߩߎޔ‬ᢱߩ⚿᥏᭴ㅧ‫ޔ‬㔚ሶ⁁ᘒࠍ᣿ࠄ߆ߦߒߡ޿ߊߎߣߪ‫ߎޔ‬ࠇ߆ࠄߩ㜞ᯏ⢻᧚ᢱࠍ㐿⊒ߒߡⴕߊ਄ߢ‫ޔ‬㕖Ᏹߦ㊀ⷐߥ⍮⷗߇ᓧࠄࠇࠆ߽ߩߣᦼᓙߐࠇࠆ‫ޕ‬
GeTe-Sb2Te3ᡆੑర♽ߪ‫⋧ޔ‬ᄌൻశ⸥㍳᧚ᢱߣߒߡఝࠇߚ․ᕈࠍᜬߟߚ߼‫ޔ‬ㄭᐕ‫ޔ‬᭽‫ߥޘ‬ߥⷺᐲ߆ࠄ‫ޔ‬ᢙᄙߊߩ⎇ⓥ߇ߥߐࠇߡ޿ࠆ‫ߩߎޕ‬ᡆੑర♽ߦ㑐ߒߡߪ‫ޔ‬ฎߊ߆ࠄ‫ޔ‬ᾲᐔⴧ⁁ᘒߢ‫ޔ‬Ge2Sb2Te5‫ޔ‬GeSb2Te4‫ޔ‬GeSb4Te7‫ߩޔ‬ਃߟߩ㊄ዻ㑆ൻว‛㧔቟ቯ⋧㧕ࠍᒻᚑߔࠆߎߣ߇⍮ࠄࠇߡ޿ߚ[5]‫ࠄࠇߎޕ‬ਃߟߩൻว‛ߪ‫ޔ‬Geጀ‫ޔ‬Sbጀ‫ޔ‬Teጀߩ‫ޔ‬ਃߟߩጀߩⓍጀ๟ᦼ߇⇣ߥߞߚ┙ᣇᦨኒలႯ᭴ㅧߣߒߡ⸥ㅀߐࠇߡ޿ࠆ‫ޕ‬Ge2Sb2Te5‫ޔ‬GeSb2Te4‫ޔ‬GeSb4Te7ߪ㗅ߦ9ጀ㧔 P 3m1 ‫ޔ‬4.20×16.96Έ㧕‫ޔ‬21ጀ㧔 R3 m ‫ޔ‬4.21×40.6Έ㧕‫ޔ‬12ጀ㧔 P 3m1 ‫ޔ‬4.21×23.65Έ㧕᭴ㅧߣߥߞߡ޿ࠆ[6], [7]‫ޔߚ߹ޕ‬GeTeߪ6ጀ᭴ㅧ[8]‫ޔ‬Sb2Te3ߪ15ጀ᭴ㅧ[9]ߣߒߡ⸥ㅀߐࠇࠆ‫ᦝޕ‬ߦㄭᐕߩ⎇ⓥߦࠃࠅ‫ࠄࠇߎޔߪ♽ߩߎޔ‬ਃ⒳ߩൻว‛ߩઁߦ߽‫⚵ޔ‬ᚑߦᔕߓߡ‫ޔ‬(GeTe)n(Sb2Te3)mߢ⸥ㅀߐࠇࠆ‫ޔ‬᭽‫ߥޘ‬㊄ዻ㑆ൻว‛‫ޔ‬ᚲ⻐‫ࠍ⋧ࠬࠟࡠࡕࡎޔ‬ᒻᚑߔࠆߎߣ
߇᣿ࠄ߆ߣߥߞߡ߈ߡ޿ࠆ[10]‫ޕ‬ᚒ‫ޔߪޘ‬SPring-8ࠍ↪޿ߚ⹦⚦ߥ⸃ᨆߦࠃࠅ‫ޔ‬Ge3Sb2Te6‫ޔ‬
Ge2Sb2Te5‫ޔ‬GeSb2Te4ߩ⹦⚦ߥ᭴ㅧ⸃ᨆߦᚑഞߒߚ‫ޔ߇ࠈߎߣޕ‬GeSb4Te7ߦߟ޿ߡߪ‫ޔ‬ฎߊ߆ࠄߘߩሽ࿷߇⷗಴ߛߐࠇߡ޿ࠆߦ᜔߽ࠊࠄߕ‫ߥ⚦⹦ߛᧂޔ‬᭴ㅧ⸃ᨆ߇ߥߐࠇߡ޿ߥ޿‫ߎޕ‬
ߩGeSb4Te7ߦട߃ߡ‫ޔ‬GeTe-Bi2Te3♽‫ޔ‬SnTe-Bi2Te3♽‫ޔ‬PbTe-Sb2Te3♽‫ޔ‬PbTe-Bi2Te3♽ߦ߅޿ߡ‫ޔ‬
GeBi4Te7 [11]‫ޔ‬SnBi4Te7[4]‫ޔ‬PbSb4Te7‫ޔ‬PbBi4Te7 [12]╬߽‫ޔ‬න৻⋧ߣߒߡ‫ࠄࠇߘޔ‬ൻว‛߇ሽ࿷ߔࠆߣᦼᓙߐࠇࠆߎߣ߆ࠄ‫੹ޔ‬࿁ߪ‫ޔ‬GeSb4Te7ߣ૬ߖߡ‫ࠄࠇߎޔ‬྾⒳ߩൻว‛ߩ⹦⚦ߥ᭴ㅧ⸃ᨆࠍⴕ޿‫ޔ‬Ყセᬌ⸛ߔࠆߎߣࠍ⋡⊛ߣߒߚ‫⃻ޔߡߒߘޕ‬࿷ߩߣߎࠈ‫ޔ‬GeBi4Te7቟ቯ⋧ߦ㑐ߒ‫ߩߘޔ‬᭴ㅧ‫ޔ‬෸߮ߘߩ㔚ሶ⁁ᘒߦߟ޿ߡ⹦⚦ߥ⸃ᨆߦᚑഞߒߚߩߢ‫⚿ߩߘޔ‬ᨐߦߟ޿ߡႎ๔ߔࠆ‫ޕ‬☳ᧃ࿁᛬᷹ቯ↪ߩ⹜ᢱߪ‫ޔ‬ᰴߦ␜ߔᣇᴺߦࠃࠅ૞ᚑߒߚ‫ޕ‬వߕ‫⚐ޔࠇߙࠇߘޔ‬ᐲ 99.999%ߩΦᣖర⚛㧔Ge, Sn, Pb㧕
‫ޔ‬V ᣖర⚛㧔Sb, Bi㧕‫ޔ‬VI ᣖర⚛㧔Te㧕ࠍ‫ޔ‬1㧦4㧦7 ߩ⚵ᚑᲧߦߡ↪
ᗧߒ‫ࠍࠄࠇߘޔ‬⍹⧷▤ౝ‫ޔ‬Ar 㔓࿐᳇ਛߢṁ⸃ߒߚ‫ޕ‬లಽߦṁ⸃‫ޔ‬ᡬᜈߒߚᓟ‫ޔ‬⍹⧷▤ߏߣ‫ޔ‬᳖᳓ਛߢᕆ಄ߒߚ‫ޕ‬ᓧࠄࠇߚࠗࡦࠧ࠶࠻ࠍ‫ޔ‬ౣ߮‫ޔ‬Ar ࠍలႯߒߚ⍹⧷▤ߦኽ౉ߒ‫ޔ‬723K ߦߡ 15 ᣣ㑆὾㊰ߒߚ‫ޕ‬ᾲಣℂߐࠇߚࠗࡦࠧ࠶࠻ߩ৻ㇱࠍ‫℺ޔ‬Å੃㋬ߢ☳⎈‫޿↪ࠍࡘࠪ࠶ࡔޔ‬ߡ☸ᐲࠍ⺞ᢛߒߚᓟ‫ޔ‬ౝᓘ 0.1㨪0.3mm ߩ⍹⧷ࠟ࡜ࠬ⵾ࠠࡖࡇ࡜࡝࡯ߦలႯߒ‫ޔ‬᡼኿శߦࠃࠆ࿁᛬ታ㛎↪⹜ᢱߣߒߚ‫ޕ‬ᄢ᳇ߣߩធ⸅ࠍㆤᢿߔࠆߚ߼‫⹜ߩ࡯࡝࡜ࡇࡖࠠޔ‬ᢱᝌ౉ญࠍࠕ࠮࠴࡟ࡦ㧛㉄⚛ᷙวࠟࠬࡃ࡯࠽࡯ߢኽߓಾߞߚ‫ޕ‬☳ᧃ࿁᛬ታ㛎ߪ㧔⽷㧕㜞ノᐲశ⑼ቇ⎇ⓥ࠮ࡦ࠲࡯㧔SPring-8㧕‫ޔ‬BL02B2 ࡜ࠗࡦ[13]ߢⴕߞ
ߚ‫ޕ‬᡼኿శߪ‫ޔ‬ੑ⚿᥏ಽశེߦࠃࠅන⦡ൻߐߖߚᓟ‫ޔ‬ᓟ⟎ࠦ࡝ࡔ࡯࠲࡯ࡒ࡜࡯ߦࠃࠅᐔⴕൻߐߖ‫ޔ‬࿁᛬ታ㛎↪౉኿ࡆ࡯ࡓߣߒߡ↪޿ߚ‫౉ޕ‬኿ࡆ࡯ࡓߩࠛࡀ࡞ࠡ࡯ߪ 29.5keV ߢ޽ࠆ‫ޕ‬࠺ࡃࠗ㧙ࠪࠚ࡜࡯ࠞࡔ࡜ߩࠞࡔ࡜ඨᓘߪ 287mm ߢ޽ࠅ‫৻ޔ‬ᣇࠗࡔ࡯ࠫࡦࠣࡊ࡟࡯࠻ߩࡇࠢ
࠮࡞ࠨࠗ࠭ߪ 100µm2 ߢ޽ࠆ‫ ⚂ߪࠇߎޕ‬0.02 㩩ߩⷺᐲಽ⸃⢻ߦኻᔕߔࠆ‫⚿ޕ‬᥏᭴ㅧߪ Rietveld
ᴺ[14]ߦࠃߞߡ♖ኒߦ᳿ቯߒߚ‫ޔߪࡓ࡜ࠣࡠࡊߚ޿↪ޕ‬RIETAN[15]ߢ޽ࠆ‫ޕ‬ේሶᢔੂ࿃ሶߪ‫ޔ‬ਛᕈߩ߽ߩࠍ↪޿ߚ‫ޕ‬Rietveld ⸃ᨆߩ♖ᐲࠍะ਄ߐߖࠆߚ߼‫ޔ‬50µm2 ߩࡇࠢ࠮࡞ࠨࠗ࠭ߦߡᒝᐲ࠺࡯࠲ࠍ⺒ߺㄟߺ‫ ⚂ޔ‬0.01 㩩ೞߺߩ࿁᛬ᒝᐲ࠺࡯࠲ࠍᓧߚ‫ޕ‬Ᏹ᷷ߦ߅޿ߡ‫ޔ‬CeO2 ᮡḰ☳ᧃ⹜ᢱ㧔a=5.4111Έ㧕ߩ࿁᛬✢߽‫ߡߒߣࠬࡦ࡟ࠔࡈ࡟ޔ‬หߓ᧦ઙߦߡ⸥㍳ߒ‫ߚ޿↪ޔ‬᡼኿శߩࠛࡀ࡞ࠡ࡯ࠍ⏕⹺ߒߚ‫ޕ‬ૐ᷷‫ޔ‬㜞᷷ታ㛎ߪ‫ޔ‬ᚲቯߩ᷷ᐲߦ⸳ቯߒߚ N2 ࠟࠬࠍࠠࡖࡇ࡜࡝࡯ߦ็߈ઃߌࠆߎߣߦࠃࠅⴕߞߚ‫ޕ‬࿁᛬᷹ቯߪ‫ޔ‬వߕ‫ޔ‬ቶ᷷߆ࠄ 723K ߦ⥋ࠆ᣹᷷ㆊ⒟ߦ߅޿ߡ‫ޔ‬Ბ㓏⊛ߦⴕߞߚ‫ߩߎޕ‬ታ㛎ߦࠃࠅ‫⹜ޔ‬ᢱ߇቟ቯ⋧ߦ⚿᥏ൻߒߡ޿ࠆߎߣ‫⹜ޔ‬ᢱ߇᭴ㅧ⸃ᨆߦ⠴߃ᓧࠆ⚿᥏ᕈࠍ₪ᓧߒߡ޿ࠆߎߣߥߤࠍ⏕⹺ߒߚ‫♖ޕ‬ኒ᭴ㅧ⸃ᨆ↪ߩ࠺࡯࠲ߪ‫⹜ޔ‬ᢱ᷷ᐲࠍ 90K ߦ⸳ቯߒ‫ޔ‬චಽߦᤨ㑆ࠍ߆ߌߡ᷹ቯߔࠆߎߣߦࠃࠅᓧߚ‫ޕ‬వߦㅀߴߚࠃ߁ߦ‫ޔ‬GeTe-Bi2Te3ᡆੑర♽߽߹ߚ‫ޔ‬GeTe-Sb 2 Te 3ᡆੑర♽ߣห᭽‫⋧ࠬࠟࡠࡕࡎޔ‬ࠍᒻᚑߔࠆߎߣ߇⍮ࠄࠇߡ߅ࠅ[16]‫⚵ޔ‬ᚑߦଐሽߒߡ‫ޔ‬Ge‫ޔ‬Bi‫ޔ‬Te ߩේሶጀߩ‫ޔ‬Ⓧጀ๟ᦼ߇⇣ߥߞߚ᭽‫┙ߩޘ‬ᣇᦨኒⓍጀဳ᭴ㅧ߇಴⃻ߔࠆ‫ޕ‬Ge 1 Bi 4 Te 7 ߪ‫ޔ‬12
ጀ᭴ㅧ㧔12P㧕ߣߥࠆߣ੍ᗐߐ
ࠇߡ޿ࠆ[7], [11]‫ޕ‬ᚒ‫ޔߪޘ‬ᣢߦㅀߴߚ߇‫ޔ‬Ge3Sb2Te6[17]‫ޔ‬
Ge2Sb2Te5[18] ‫ ޔ‬GeSb2Te4[10],Fig. 1.
Observed (+) and calculated (gray line) X-ray diffraction
profiles of Ge1Bi4Te7 at 90 K. Profiles are shown in logarithmic
scale, and under them, the reflection markers are indicated byvertical spikes. A difference curve (observed-calculated) appears at
the top of the Figure in a linear scale.

[19]‫ޔ‬Ge2Bi2Te5[20]ߦߟ޿ߡߪ‫♖ޔ‬ኒߥ᭴ㅧ⸃ᨆࠍⴕߞߡ߅ࠅ‫ޔߪࠄࠇߘޔ‬㗅ߦ‫ޔ‬33 ጀ‫ޔ‬9ጀ‫ޔ‬21 ጀ‫ޔ‬9 ጀ᭴ㅧߣߥߞߡ޿ߚ‫⚵ޔߡߒߘޕ‬ᚑ߆ࠄ੍ᗐߐࠇࠆࠃ߁ߦ‫ޔ‬Ge2Sb2Te5 ߣ Ge2Bi2Te5ߪ‫ޔ‬หဳߩ᭴ㅧߣߥߞߡ޿ߚ‫ߩࠄࠇߎޔࠄ߇ߥߒ߆ߒޕ‬᭴ㅧߦ߅޿ߡߪ‫ޔ‬Ge‫ޔ‬Sb(Bi)߇‫ޔ‬ᓥ᧪⠨߃ࠄࠇߡ޿ߚ߽ߩߣߪ⇣ߥࠅ‫ޔࠇߙࠇߘޔ‬࿕᦭ߩࠨࠗ࠻㧔ጀ㧕ࠍභ᦭ߒߡ޿ࠆߩߢߪ
ߥߊ‫ޔ‬Ge‫ޔ‬Sb(Bi)ߩⶄᢙߩࠨࠗ࠻ߦ〙ߞߡ‫ޔ‬ᷙߓࠅวߞߡභ᦭ߒߡ޿ࠆߎߣ߇᣿ࠄ߆ߣߥߞߚ‫ ߩߎޔࠄ߆ߣߎߩࠄࠇߎޕ‬Ge1Bi4Te7 ቟ቯ⋧߽‫ޔ‬12 ጀߩ᭴ㅧࠍᜬߜ‫ ߡߒߘޔ‬Ge‫ޔ‬Bi ߩ࡜ࡦ࠳ࡓߥභ᦭߇ሽ࿷ߔࠆߣߒߡ᭴ㅧ⸃ᨆࠍⴕߞߚ‫ޕ‬Agaev [7]‫ޔ‬Shelimova [11]‫ ޔ‬Shu [21]╬ߦࠃࠆߣ‫ޔ‬Ge‫ޔ‬Bi ߩขࠅ߁ࠆࠨࠗ࠻ߪ‫ޔ‬ⓨ㑆⟲㧦 P 3m1 ߦ߅޿ߡ‫ ߩߟ৻ޔ‬1(b)ߣੑߟߩ 2(d)ࠨࠗ࠻ߢ޽ࠆ㧔⴫ I ෳᾖ㧕‫ޕ‬ᚒ‫࠻ࠗࠨߩࠄࠇߎޔߪޘ‬㑆ߢ‫ޔ‬

2: 2 dg Ge

2: 2 d
5: 2 d1  g Bi㧘 g Ge5: 2 d7:1b
1  g Bi㧘 g Bi2: 2 d
5: 2 d7:1b
7:1b4  2 u g Bi
 2 u g Bi, g Ge
1  g Bi2: 2 d
5: 2 dߥࠆ᧦ઙࠍ⺖ߒ‫ ޔ‬g Bi
෸߮ g Biࠍ⁛┙ᄌᢙߣߒߡ⸃ᨆࠍㅴ߼ߚ‫ ޔߢߎߎޕ‬g XY ߦ߅ߌࠆ X

෸߮ Y ߪ‫ޔࠇߙࠇߘޔ‬ේሶ⒳‫ޔ‬ේሶࠨࠗ࠻ࠍ⴫ߒߡ޿ࠆ‫ޕ‬g ߪභ᦭₸ߢ޽ࠆ‫ ⴫ޕ‬I‫ޔ‬࿑ 1㧔TableI‫ޔ‬Fig. 1㧕ߦ␜ߐࠇࠆࠃ߁ߦ‫ߩߎޔ‬઒ቯߦࠃࠅలಽߦḩ⿷ߩࠁߊ⸃ᨆ⚿ᨐ߇ᓧࠄࠇߚ‫ޕ‬
Ge1Bi4Te7 ቟ቯ⋧ߩ⚿᥏᭴ㅧߪ‫ޔ‬ฦጀࠍ [ 1 10] ᣇะߦ 1/3 ߕߟࠪࡈ࠻ߐߖߥ߇ࠄⓍߺ਄ߍߚ‫ޔ‬
12 ጀ๟ᦼߩ┙ᣇᦨኒ᭴ㅧߣߥߞߡ޿ࠆ㧔࿑ 2㧛Fig. 2㧕‫ޕ‬Te ߪ‫ޔ‬㧟ߟߩ࿕᦭ࠨࠗ࠻㧔ጀ㧕ࠍ‫ޔ‬100%‫ޔ‬භ᦭ߒߡ޿ࠆ߇‫৻ޔ‬ᣇ Ge‫ޔ‬Bi ߪ‫ߩઁޔ‬㧟ߟߩࠨࠗ࠻‫ޔ‬2: 2d‫ޔ‬5: 2d‫ޔ‬7: 1b ߦ〙ߞߡ‫ޔ‬࡜ࡦ࠳ࡓߦභ᦭ߒߡ޿ࠆ‫ޔߛߚޕ‬ฦࠨࠗ࠻ߩ Ge㧛Bi Ყߪ‫ࠆࠃߦ࠻ࠗࠨޔ‬ಽᏓ߇ⷰࠄࠇࠆ‫ޕ‬

Table I
Refined structural parameters for Ge1Bi4Te7 at 90 K. The space group is P 3m1 . Standard
deviations are shown in parentheses. Final R-factors and lattice parameters are Rwp = 5.30%, Rp = 1.20%, RI= 1.20%, Rwp expected = 1.49%, a = 4.3450 (1) Å, and c = 23.8205 (8) Å.

AtomSitegxyz

B(Å2)

Te(1)

1:1(a)

1.00001.00(4)Ge/Bi(1)2:2(d)

0.074 / 0.926(7)

1/3

2/3

0.0843 (1)0.77(2)Te(2)3:2(d)

1.0

2/3

1/3

0.1576 (2)

1.00

Te(3)

4:2(c)

1.000

0.2670 (2)1.00

Ge/Bi(2)5:2(d)

0.197 / 0.803(5)

1/3

2/3

0.3383 (1)

0.77

Te(4)

6:2(d)

1.0

2/3

1/3

0.4254 (2)1.00

Ge/Bi(3)

7:1(b)

0.458 / 0.542

00

1/2

0.77

ߎߩᲧ㧔භ᦭௑ะ㧕߆ࠄ‫ߩߎޔ‬᭴ㅧߩ‫ޔ‬ℂᗐ⊛ߥ㧔ቢోߦ⒎ᐨ㈩೉ߒߚ᭴ㅧߩ㧕ጀߩⓍߺ
㊀ߥࠅᣇߪ‫ޔ‬

Te Bi Te Te Bi Te Ge Te Bi Te Te Bi   
a b c a b c a b c a b cߣߥࠆ߽ߩߣ⠨߃ࠄࠇ‫ޔߪࠇߎޔ‬Agaev [7]‫ޔ‬Shelimova [11]‫ ޔ‬Shu[20]╬ߩ੍ᗐߒߚ᭴ㅧߣ
╬ߒߊߥࠆ㧔࿑ 2㧛Fig . 2㧕‫ߩߎޕ‬ℂᗐ⊛ߦ㈩૏ߒߚ᭴ㅧࡕ࠺࡞㧔perfectly ordered structuralmodel㧕ࠍ↪޿‫࠼ࡦࡃޔ‬㧔DFT㧛Density Functional
Theory㧕⸘▚[21]ࠍⴕߞߡߺߚ‫ޕ‬࿑ 3㧔Fig. 3㧕߇‫ޔ‬ᓧࠄࠇߚ⁁ᘒኒᐲߢ޽ࠆ‫⚿ޕ‬ᨐߪ‫ߎޔ‬ߩൻว‛߇‫⚿ߩߘ߽ߒ߽ޔ‬᥏᭴ㅧ߿‫⚿ޔ‬᥏⚵❱ߦ‫ߊోޔ‬ᰳ㒱߇ߥ޿ߣ઒ቯߔࠇ߫‫ޔ‬㕖Ᏹߦ⁜޿⑌೙Ꮺࠍ߽ߞߚඨዉ૕‛⾰ߢ޽ࠆߎߣࠍ␜ߒߡ޿ࠆ‫ޕ‬Shelimova ╬[22]ߪ‫ޔ‬ታ㛎⊛ߦ‫ߩߎޔ‬ൻว‛߇‫ޔ‬n ဳ❗Ꮺඨዉ૕ߢ޽
ࠆߎߣࠍ⷗಴ߛߒߡ߅ࠅ‫❗ߩߘޔ‬ㅌ߇‫ޔ‬᭴ㅧᰳ㒱ߦ⿠࿃ߔࠆ߽ߩߢ޽ࠆߣߒߡ޿ࠆ‫ޕ‬

Fig. 2. Atomic configuration of Ge1Bi4Te7 in the(hypothetical) perfect ordered structure model
shown in a stereo graphic view, in which red,yellow, and red spheres represent Ge, Bi, and Te
atoms, respectively.

౨㗡ߢ߽ㅀߴߚ߇‫ޔ‬GeTe-Sb2Te3 ᡆੑర♽ൻว‛ߪ‫⋧ޔ‬ᄌൻశ⸥㍳᧚ᢱߣߒߡ‫⃻ޔ‬࿷‫߽ᦨޔ‬ᐢߊ↪޿ࠄࠇߡ޿ࠆ‫᧚ߩߎߚ߹ޕ‬ᢱߪ‫ޔ‬
శ⸥㍳ߩߺߥࠄߕ‫ޔ‬ਇើ⊒ᕈߩ㔚᳇ࡔࡕ࡝࡯᧚ᢱߣߒߡ߽‫ޔ‬ᤓ੹‫߁ࠃࠆࠇࠄ޿↪ߦࠎ⋓ޔ‬

15ߦߥߞߡ߈ߚ‫ߩߘޕ‬ℂ↱ߪ‫ߩߎޔ‬ൻDOS (states/eV)ว‛ߩᜬߟḰ቟ቯ⋧ߩ᭴ㅧ߇‫ࡕࠕޔ‬࡞ࡈࠔࠬߩේሶ㈩೉ߦᭂ߼ߡធㄭ

10ߒߚ߽ߩߣߥߞߡ߅ࠅ‫ޔ‬㜞ㅦ⋧ᄌൻ㧔㜞ㅦᦠ឵㧕߇น⢻ߥߚ߼ߢ޽ࠆ‫ޕ‬5ߒ߆ߒߥ߇ࠄ‫৻ޔ‬ᣇߢ‫ߩߎޔ‬ൻว‛ߪ‫ޔ‬ᾲᐔⴧ⁁ᘒߦ߅޿ߡߪ‫ޔ‬5R‫ޔ‬7R‫ޔ‬
9P‫ޔ‬11R‫ޔ‬13R‫ޔ‬15P‫ޔ‬17R‫ޔ‬19R‫ޔ‬

0-15-10-505̖‫┙ޔߩ╬ޔ‬ᣇᦨኒⓍጀࠍၮᧄߣߒ

Energy (eV)Fig. 3. DOS diagram for Ge1Bi4Te7 obtained using bandcalculation. The Fermi level corresponds to 0 eV. This
calculation was performed using the perfectly orderedstructure model with a 100% Te-Te interlayer gap (see Fig. 2).
A narrow band gap can be seen between the valence andconduction bands at the Fermi level.

ߚ㕖Ᏹߦⶄ㔀ߥ㐳๟ᦼ᭴ㅧ߇‫⚵ޔ‬ᚑߦᔕߓㅪ⛯⊛ߦ಴⃻ߒࡎࡕࡠࠟࠬ
⋧ࠍᒻᚑߔࠆ‫ޔߚ߹ޕ‬ห᭽ߦ‫ޔ‬
GeTe-Bi2Te3 ♽ ‫ ޔ‬SnTe-Bi2Te3 ♽ ‫ޔ‬
PbTe-Sb2Te3 ♽‫ޔ‬PbTe-Bi2Te3 ♽߽ࡎࡕࡠࠟࠬ⋧ࠍᒻᚑߔࠆ‫ࠄࠇߎޕ‬ൻว‛ߪ‫ޔ‬ᾲ㔚ᄌ឵᧚ᢱߣߒߡ᦭ᦸߥ․ᕈࠍ␜ߔߎߣ߇⍮ࠄࠇߡ߅ࠅ‫⋧ޔ‬ᄌൻ⸥㍳ߩߺߥࠄߕ‫࡯ࠡ࡞ࡀࠛޔ‬ᄌ឵࠺ࡃࠗࠬ↪ㅜߣߒߡ߽ᵈ⋡ߐࠇߟߟ޽ࠆ‫੹ޕ‬ᓟ‫ޔ‬Ḱ቟ቯ⋧ߩߺߥࠄߕ‫᧚ࠄࠇߎޔ‬ᢱߩ቟ቯ⋧ߩ᭴ㅧ߽♖ኒߦ⸃ᨆߔࠆߎߣߦࠃࠅ‫ޔ‬᭴ㅧߣ‫‛ޔ‬ᕈߣߩ㑐ଥࠍ⸃߈᣿߆ߒ‫᧚޿⦟ࠅࠃޔ‬ᢱ㐿⊒ࠍടㅦߐߖߚ޿ߣ⠨߃ߡ޿ࠆ‫ޕ‬Ӌᎋ૨ྂᴾ[1][2]Yamada, N.; Ohno, E.; Nishiuchi, K.; Akahira, N.; Takao, M. J. Appl. Phys. 69(5), 1 (1991), 2849.
Matsunaga, T., Kojima, R., Yamada, N., Kifune, K., Kubota, Y., Tabata, Y., Takata, M.; Inorg. Chem. 45(2006), 2235.

[3]

Matsunaga, T.; Yamada, N. Jpn. J. Appl. Phys. 43, 7B (2004), 4704.

[4]Shelimova L. E., Karpinskii O. G., Konstantinov P. P., Avilov E. S., Kretova M. A., and Zemskov V. S.; Inorg.
Mater. 40, 5 (2004), 451.

[5]Abrikosov, N. Kh., Danilova-Dobryakova, G. T.; Izv. Akad. Auk. SSSR Neorg. Mater. 1, (1965), 204.

[6]Petrov, I. I., Imamovet, R. M., Pinsker, Z. G..; Sov. Phys. Crystallogr. 13 (1968), 339.

[7]Agaev, K. A., Talybov, A. G.; Sov. Phys. Crystallogr. 11 (1966), 400.

[8]Goldak, J., Barrett, C. S., Innes, D., Youdelis, W.; J. Chem. Phys. 44 (1966), 3323.

[9]

Anderson, T. L., Krause, H. B.; Acta Crystallogr. B30 (1974), 1307

[10] Karpinsky O. G., Shelimova L. E., Kretova M. A., Fleurial J. P.; J. Alloys Compd. 268 (1998), 112.
[11] Shelimova L. E., Karpinskii O. G., Konstantinov P. P., Kretova, M. A., Avilov, E. S., Zemskov, V. S.; Inorg.
Mater. 38, 8 (2002), 790.
[12] Shelimova L. E., Svechnikova, T. E., Konstantinov P. P., Karpinskii O. G., Avilov, E. S., Kretova, M. A.,Zemskov, V. S.; Inorg. Mater. 43, 2 (2007), 125.
[13] Nishibori, E., Takata, M., Kato, K., Sakata, M., Kubota, Y., Aoyagi, S., Kuroiwa, Y., Yamakata, M., Ikeda, N.;
Nucl. Instrum. Methods A467-468 (2001), 1045
[14] Rietveld, H. M.; J. Appl. Cryst. 2 (1969), 65[15] Izumi, F., Ikeda, T.; Mater. Sci. Forum 321-324 (2000), 198

[16] Shelimova L. E., Karpinskii O. G., Zemskov, V. S., Konstantinov P. P.; Inorg. Mater. 36, 3 (2000), 235.
[17] Matsunaga, T., Kojima, R., Yamada, N., Kifune, K., Kubota, Y., Takata, M.; Appl. Phys. Lett. 90 (2007),
161919[18] Matsunaga, T., Yamada, N., Kubota, Y.; Acta crystallogr. B60 (2004), 685.
[19] Matsunaga, T., Yamada, N.; Phys. Rev. B69 (2004), 104111.
[20] Matsunaga, T., Kojima, R., Yamada, N., Kifune, K., Kubota, Y., Takata, M.; Acta crystallogr. B36 (2007), 346[21] CHASE–3PT: The “PHASE” computer program was created by the members of the national project “FrontierSimulation Software for Industrial Science (FSIS),” and Advancesoft Co., Ltd., has developed and released thissoftware as “Advance/PHASE” (http://www.advancesoft.jp/)[22] Shu, H. -W., Jaulmes, S., Flahaut, J.; J. Solid State Chem. 74 (1988), 277.

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