࠙◊✲㒊ࠚ ◊ ✲ ㄢ 㢟 ྡ ↓ᶵᒙ≧ྜ≀ࡢບ㉳ᏊⓎගࡼࡿࢩࣥࢳ࣮ࣞࢱᮦᩱࡢ᥈⣴ ◊✲௦⾲⪅ྡ Ⲷ㔝 ᣅ ◊✲ศᢸ⪅ྡ ྜྷᕝᙲ ᮾᏛ㔠ᒓᮦᩱ◊✲ᡤ 㸯㸬ࡣࡌࡵ 㝧㟁Ꮚ᩿ᒙീ⨨ࡸ X ⥺ CT ࡢ᳨▱㒊ࠊ✵ ࡢᡭⲴ≀᳨ᰝᶵ࡞ ⏝࠸ࡽࢀࡿᨺᑕ⥺᳨ฟჾࡣࠊᨺᑕ⥺ࢆ⣸እ㹼ྍどගኚࡍࡿࢩࣥࢳ࣮ࣞ Se ࢱࠊࡑࡢගࢆ㟁Ẽಙྕኚࡍࡿཷග⣲Ꮚࡽ࡞ࡗ࡚࠾ࡾࠊࡑࡢᛶ⬟ Ag ࡣࢩࣥࢳ࣮ࣞࢱࡢ≉ᛶࡁࡃ౫Ꮡࡍࡿࠋࢩࣥࢳ࣮ࣞࢱࡣᛂ⏝ୖ㧗Ⓨග㔞 Ba ࡘ▷ᑑ࡛࠶ࡿࡇࡀᮃࡲࡋ࠸ࡀࠊ⌧≧ࡢᕼᅵ㢮Ⓨග୰ᚰࢆ⏝࠸ࡿࢩࣥ ࢳ࣮ࣞࢱࡣືᏊᙉᗘࡢไ⣙ࡽࠊࡇࢀ௨ୖࡢ≉ᛶࡢྥୖࡣ㞴ࡋ࠸ࠋࡑࡇ ࡛Ⓨගཎ⌮ࡋ࡚༙ᑟయࡢບ㉳ᏊⓎගࢆ⏝࠸ࡿࡇࡀヨࡳࡽࢀ࡚࠾ࡾࠊ ZnO ࡸ PbI2 ࡞࠸ࡃࡘࡢྜ≀࡛ᐊ ࡛ࡢⓎග㔞ࡣ㠀ᖖప࠸ࡶࡢ RE ࡢࠊ▷ᑑ࡞ࢩࣥࢳ࣮ࣞࢩࣙࣥ≉ᛶࡀሗ࿌ࡉࢀ࡚࠸ࡿࠋ୍᪉༢⣧࡞༙ᑟయ O ࡛ࡣ࡞ࡃ᭷ᶵ⤯⦕య㸫↓ᶵ༙ᑟయᒙࢆ✚ᒙࡉࡏࡿࡇ࡛ࠊ㔞Ꮚ㛢ࡌ㎸ࡵຠ ᯝࡼࡾᐊ ࡛ࡶ▷ᑑࡘẚ㍑ⓗ㧗࠸Ⓨග㔞ࢆ♧ࡍྜ≀ࡀⓎぢࡉࢀ ࡓ[1]ࠋࡇࡢ≀㉁ࡣ᭷ᶵᒙࢆྵࡴࡇࡽᨺᑕ⥺㜼Ṇ⬟ࡀ㠀ᖖపࡃࠊ≀ᛶ ホ౯ࡶ㟁Ꮚ⥺↷ᑕࡼࡿࡶࡢࡢࡳ␃ࡲࡗ࡚࠸ࡿࡀࠊྠᵝࡢᵓ㐀ࢆ↓ᶵ ྜ≀࡛ᐇ⌧࡛ࡁࢀࡤ᪤Ꮡࢩࣥࢳ࣮ࣞࢱᑐࡍࡿࡁ࡞ඃᛶࢆ᭷ࡍࡿࡇ ࡀᮇᚅ࡛ࡁࡿࠋ⏦ㄳ⪅ࡣࡈࡃ᭱㏆ࠊ㓟⣲◲㯤࣭㓟⣲◉⣲࡞」ᩘࡢ Fig. 1 Crystal structure of ࢽ࢜ࣥࢆྵࡴ⣔㸦௨ୗࠊᒙ≧」ྜࢽ࢜ࣥྜ≀⛠㸧࠾࠸࡚ࠊ㉸ (Ag2Se2)(Ba3RE2O5) ఏᑟᒙࡀᩘ nm ࡢ㠀ᖖཌ࠸⤯⦕ᒙ࡛㝸࡚ࡽࢀࡓྜ≀ࡀ⏕ᡂࡍࡿࡇ ࢆⓎぢࡋࡓࠋࡑࡇ࡛ࠊࡇࡢ≉␗࡞ᒙ≧ᵓ㐀ࢆ⏝ࡋ࡚⤯⦕య㸫༙ᑟయᒙࡀ✚ᒙࡋࡓྜ≀ࢆྜᡂࡋࠊᒙ≧ ↓ᶵࢩࣥࢳ࣮ࣞࢱࡋ࡚ࡢྍ⬟ᛶࢆ᥈ࡿࡇࢆᅗࡋࡓࠋ － 194 － 220 217 1114 200 RE = Sm Intensity / arb. units 㸱㸬◊✲ᡂᯝ Ag, Se, Ba, BaO2, RE2O3(RE = Sc, Y, Sm ~ Lu)➼ࡢཎᩱࢆ Ꮫ㔞ㄽẚ࡞ࡿࡼ࠺⛗㔞ࡋࠊᅛ┦ᛂἲ࡚ 900 ~ 1100Υ ࡛ 24 h ↝ᡂࡍࡿࡇ࡛ከ⤖ᬗヨᩱࢆྜᡂࡋࡓࠋヨᩱࡣ⢊ᮎ X ⥺ᅇᢡἲࡼࡿ┦ࡢྠᐃ᱁Ꮚᐃᩘࡢホ౯ࠊSQUID ☢᮰ ィࡼࡿ☢⋡ࡢ ᐃཬࡧᣑᩓᑕ⋡ ᐃࢆ⾜ࡗࡓࠋ ⣔ ⤫ ⓗ ࡞ ≀ ㉁ ᥈ ⣴ ࡢ ⤖ ᯝ ࠊ Fig. 2 ࡢ ࡼ ࠺ (Ag2Se2)(Ba3RE2O5) (RE = Sc, Y, Sm ~ Lu)ࡢ 12 ✀㢮ࡢ᪂つ ྜ≀ࡢྜᡂᡂຌࡋࡓࠋࡇࢀࡽࡢྜ≀ࡣ࠸ࡎࢀࡶ Fig. 1 ♧ࡍࡼ࠺ Ag2Se2 ᒙ Ba3RE2O5 ᒙࡀ✚ᒙࡋࡓᵓ㐀ࢆ᭷ ࡋ࡚࠾ࡾࠊࡇࡢ࠺ࡕᕼᅵ㢮ඖ⣲ࡣ࣌ࣟࣈࢫ࢝ࢺᒙࡢ 6 㓄 ࢧࢺࢆ༨᭷ࡋ࡚࠸ࡿࠋ༢⣧࣌ࣟࣈࢫ࢝ࢺ㓟≀࠾࠸࡚ RE3+࢜ࣥࡀ 6 㓄ࢧࢺࢆ༨ࡵࡿࡣ࡞࠸ࡀࠊᮏ ྜ≀୰࡛ࡣ࣌ࣟࣈࢫ࢝ࢺᒙࡀ Ag2Se2 ᒙ✚ᒙࡍࡿࡇ࡛ࠊ 107 116 110 㸰㸬◊✲⤒㐣 ᒙ≧」ྜࢽ࢜ࣥྜ≀ࡢ࠺ࡕࠊLaCuSO࣭LaCuSeO ࡣ༙ᑟయ㸫⤯⦕యᒙࡀ➨୍✀㔞Ꮚᡞྠᵝࡢ ᵓ㐀ࢆᙧᡂࡋࠊບ㉳ᏊⓎගࢆ♧ࡍࡇࡀሗ࿌ࡉࢀ࡚࠸ࡿ[2]ࠋ⏦ㄳ⪅ࡽࡣ᭱㏆ࠊ㓟≀㸫◉≀ᒙࡀ✚ᒙࡋ ࡓᒙ≧」ྜࢽ࢜ࣥྜ≀࠾࠸࡚ࠊ㉸ఏᑟᒙࡀ㠀ᖖཌ࠸⤯⦕యᒙ㝸࡚ࡽࢀࡓᒙ≧ྜ≀ࢆከᩘぢฟ ࡋࡓ[3]ࠋ᭦ࡇࡢ▱ぢࢆ༙ᑟయ㸫⤯⦕యᒙ࡞ࡿ⣔㐺⏝ࡋࡓ⤖ᯝࠊ༙ᑟయ㸫⤯⦕యᒙࡀ✚ᒙࡋࡓᵓ㐀ࢆ ᭷ࡍࡿ᪂≀㉁࡛࠶ࡿ(Cu2S2)(Sr3Sc2O5)ཬࡧ(Cu2S2)(Sr4Sc2O6)ࢆⓎぢࡋࠊࡇࡢྜ≀ࡀᐊ ࡛ບ㉳ᏊⓎගࢆ ♧ࡍྜ≀࡛࠶ࡿࡇࠊ⤖ᬗᵓ㐀ࡼࡾ≉ᛶࢆไᚚ࡛ࡁࡿࡇࢆ᫂ࡽࡋࡓ[4]ࠋࡑࡇ࡛ᖺᗘࡣࠊྠᵝ ༙ᑟయᒙ㸫⤯⦕యᒙࡀ✚ᒙࡋࡓྜ≀ࡢ᥈⣴ࢆ㐍ࡵࠊ≉ AgSe ᒙ࣌ࣟࣈࢫ࢝ࢺᆺ㓟≀ᒙࡀ✚ᒙ ࡋࡓྜ≀ࢆ᥈⣴ࡋࠊⓎぢࡋࡓྜ≀ࡘ࠸࡚ࡣ☢ᛶࡸගᏛ ≉ᛶࡢホ౯ࢆ⾜ࡗࡓࠋ RE = Gd RE = Y RE = Lu RE = Sc 2T / deg.(Cu-KD) Fig. 2 Powder XRD patterns of (Ag2Se2)(Ba3RE2O5). 12 㓄ࡢ㔠ᒓࢧࢺ༙࢜ࣥᚄࡢࡁ࠸ Ba2+ࢆ⏝࠸ࡿࡇࡀ࡛ࡁࡿࡓࡵ࡞༨᭷ࡀྍ⬟࡞ࡗ࡚࠸ ࡿࠋࡲࡓ RE ࡢ✀㢮ࡼࡾࠊ᱁Ꮚᐃᩘࡣ a = 4.22, c = 28.66 Å(RE = Sc)ࡽ a = 4.49, c = 28.53 Å(RE = Sm) ࡲ࡛ኚࡋࡓࠋࡇࢀࡽࡢྜ≀ࡢ☢⋡ࢆ ᐃࡋࡓࡇࢁࠊ࠸ࡎࢀࡢྜ≀ࡶᣲືࡣᖖ☢ᛶⓗ࡛ࠊRE3+ࡢ ✀㢮ࡼࡗ࡚☢ࡢ⤯ᑐ್ࡀኚࡋࠊ㍍ᕼᅵ㢮ࡽ୰ᕼᅵ㢮࡛☢ࡀቑࠊ㔜ᕼᅵ㢮࡛ࡣῶᑡࡍࡿࡇࡀ ศࡗࡓ(Fig.3)ࠋAgSe ᒙࡣ☢ࢇᙳ㡪ࡋ࡞࠸ࡓࡵࠊ࣌ࣟࣈࢫ࢝ࢺᒙࡢ RE3+ࡢ☢ࡢࡳࡀほ ࡉࢀ࡚࠸ࡿࡇ࡞ࡿࡀࠊࡇࢀࡣᐃᛶⓗࡣᕼᅵ㢮ࡢゅ㐠ື㔞㔞Ꮚᩘ J ౫Ꮡࡋ࡚࠸ࡿ⪃࠼ࡽࢀࡿࠋ (Ag2Se2)(Ba3Lu2O5)ࡢᣑᩓᑕ⋡ ᐃࡽࠊࡇࡢྜ≀ࡣࣂࣥࢻࢠࣕࢵࣉࡀ⣙ 2.5 eV ࡢ┤᥋㑄⛣ᆺ༙ᑟ య࡛࠶ࡿࡇࡀศࡗࡓࠋࡇࢀࡣ Ag2Se ࡢࣂࣥࢻࢠࣕࢵࣉࡋ࡚ሗ࿌ࡉࢀ࡚࠸ࡿ್㸦Eg = 0.15 eV[2]㸧ࡼ ࡾࡶ࡞ࡾࡁ࠸ࠋࡇࢀࡽࡢྜ≀ࡘ࠸࡚ࠊᘬࡁ⥆ࡁගᏛ≉ᛶࡢホ౯ࢆ⾜ࡗ࡚࠸ࡃணᐃ࡛࠶ࡿࠋ 2 4 0.2 3 FC 0.1 2 ZFC 1 0 0 0 100 0 100 200 T / K H = 1000 Oe T/K 200 300 1 0 0 RE = Ho ~ Lu Ho Er Tm Yb Lu 0.3 M / emu mol-1Oe-1 3 Dy Tb Gd Eu Sm Y 5 0.3 M / emu mol-1Oe-1 M / emu mol-1Oe-1 4 RE = Y, Sm ~ Dy M / emu mol-1Oe-1 5 0.2 FC ZFC 0.1 0 0 100 100 T/K T/K 200 Fig. 3 Temperature dependence of magnetization for (Ag2Se2)(Ba3RE2O5) References [1] K. Shibuya et al., Jpn. J. Appl. Phys. 43 (2004) L1333-L1336 [2] K. Ueda et al., Appl. Phys. Lett. 78 (2001) 2333 [3] H. Ogino et al., Appl. Phys. Lett. 97 (2010) 072506 [4] H. Ogino et al., Appl. Phys. Lett. 101 (2012) 191901 － 195 － 200 300
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