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«Â³ñíèê Õàðê³âñüêîãî óí³âåðñèòåòó», ¹ 763, 2007 ñåð³ÿ ô³çè÷íà «ßäðà, ÷àñòèíêè, ïîëÿ», âèï. 1 /33/

Ð.Â. Âîâê Âïëèâ ïîïåðå÷íîãî ìàãí³òíîãî ïîëÿ íà...

PACS: 74.25.Fy, 74.40.+k;74.72.-h; ɍȾɄ 538.945+537.312.62

ȼɉɅɂȼ ɉɈɉȿɊȿɑɇɈȽɈ ɆȺȽɇȱɌɇɈȽɈ ɉɈɅə ɇȺ ɎɅɍɄɌɍȺɐȱɃɇɍ ɉȺɊȺɉɊɈȼȱȾɇȱɋɌɖ ɅȿȽɈȼȺɇɂɏ ȺɅɘɆȱɇȱȯɆ ɆɈɇɈɄɊɂɋɌȺɅȱȼ YBa2Cu3-zAlzO7-į Ɂ ɁȺȾȺɇɈɘ ɌɈɉɈɅɈȽȱȯɘ ȾȼȱɃɇɂɄɈȼɂɏ Ɇȿɀ
ɏɚɪɤɿɜɫɶɤɢɣ ɧɚɰɿɨɧɚɥɶɧɢɣ ɭɧɿɜɟɪɫɢɬɟɬ ɿɦ. ȼ.ɇ. Ʉɚɪɚɡɿɧɚ ɍɤɪɚʀɧɚ, 61077, ɦ. ɏɚɪɤɿɜ-77, ɩɥ. ɋɜɨɛɨɞɢ, 4 email: Ruslan.V.Vovk@univer.kharkov.ua ɉɨɫɬɭɩɢɥɚ ɞɨ ɪɟɞɚɤɰɿʀ 14 ɛɟɪɟɡɧɹ 2007 ɪ. ȼ ɪɨɛɨɬɿ ɞɨɫɥɿɞɠɟɧɨ ɜɩɥɢɜ ɩɨɫɬɿɣɧɨɝɨ ɦɚɝɧɿɬɧɨɝɨ ɩɨɥɹ ɞɨ 12,7 ɤȿ ɧɚ ɬɟɦɩɟɪɚɬɭɪɧɿ ɡɚɥɟɠɧɨɫɬɿ ɟɥɟɤɬɪɨɩɪɨɜɿɞɧɨɫɬɿ ɥɟɝɨɜɚɧɢɯ ɚɥɸɦɿɧɿɽɦ ɦɨɧɨɤɪɢɫɬɚɥɿɜ YBaCuO ɡ ɫɢɫɬɟɦɨɸ ɨɞɧɨɫɩɪɹɦɨɜɚɧɢɯ ɞɜɿɣɧɢɤɨɜɢɯ ɦɟɠ. ȼ ɛɚɡɢɫɧɿɣ ab-ɩɥɨɳɢɧɿ ɜɢɡɧɚɱɟɧɿ ɬɟɦɩɟɪɚɬɭɪɧɿ ɡɚɥɟɠɧɨɫɬɿ ɧɚɞɥɢɲɤɨɜɨʀ ɩɚɪɚɩɪɨɜɿɞɧɨɫɬɿ ɿ ɩɨɥɶɨɜɚ ɡɚɥɟɠɧɿɫɬɶ ɞɨɜɠɢɧɢ ɤɨɝɟɪɟɧɬɧɨɫɬɿ [ɫ(0,ɇ) ɜɡɞɨɜɠ ɨɫɿ ɫ. Ɍɟɦɩɟɪɚɬɭɪɧɿ ɡɚɥɟɠɧɨɫɬɿ ɧɚɞɥɢɲɤɨɜɨʀ ɩɚɪɚɩɪɨɜɿɞɧɨɫɬɿ ɿɧɬɟɪɩɪɟɬɭɸɬɶɫɹ ɜ ɦɟɠɚɯ ɬɟɨɪɟɬɢɱɧɨʀ ɦɨɞɟɥɿ ɮɥɭɤɬɭɚɰɿɣɧɨʀ ɩɪɨɜɿɞɧɨɫɬɿ ɏɿɤɚɦɿ-Ʌɚɪɤɿɧɚ ɞɥɹ ɲɚɪɭɜɚɬɢɯ ɧɚɞɩɪɨɜɿɞɧɢɯ ɫɢɫɬɟɦ. Ɉɛɝɨɜɨɪɸɸɬɶɫɹ ɩɪɢɱɢɧɢ ɩɪɢɝɧɿɱɟɧɧɹ ɬɪɢɜɢɦɿɪɧɢɯ ɧɚɞɩɪɨɜɿɞɧɢɯ ɮɥɭɤɬɭɚɰɿɣ ɬɚ ɧɟɦɨɧɨɬɨɧɧɨʀ ɡɚɥɟɠɧɨɫɬɿ [ɫ(0,ɇ) ɜ ɫɥɚɛɤɢɯ ɦɚɝɧɿɬɧɢɯ ɩɨɥɹɯ ɩɪɢ ɨɪɿɽɧɬɚɰɿʀ ɜɟɤɬɨɪɚ ɦɚɝɧɿɬɧɨɝɨ ɩɨɥɹ ɜɡɞɨɜɠ ɨɫɿ ɫ. ɄɅɘɑɈȼȱ ɋɅɈȼȺ: ɮɥɭɤɬɭɚɰɿɣɧɚ ɩɪɨɜɿɞɧɿɫɬɶ, ɦɨɧɨɤɪɢɫɬɚɥɢ YBa2Cu3O7-į, ɥɟɝɭɜɚɧɧɹ, ɦɟɠɿ ɞɜɿɣɧɢɤɿɜ, ɤɪɨɫɨɜɟɪ, ɞɨɜɠɢɧɚ ɤɨɝɟɪɟɧɬɧɨɫɬɿ.

Ɋ.ȼ. ȼɨɜɤ

əɤ ɜɿɞɨɦɨ, ɜɢɫɨɤɨɬɟɦɩɟɪɚɬɭɪɧɿ ɧɚɞɩɪɨɜɿɞɧɿ ɫɩɨɥɭɤɢ (ȼɌɇɉ) ɯɚɪɚɤɬɟɪɢɡɭɸɬɶɫɹ ɧɚɹɜɧɿɫɬɸ ɲɢɪɨɤɨʀ ɮɥɭɤɬɭɚɰɿɣɧɨʀ ɞɿɥɹɧɤɢ ɧɚ ɬɟɦɩɟɪɚɬɭɪɧɢɯ ɡɚɥɟɠɧɨɫɬɹɯ ɩɪɨɜɿɞɧɨɫɬɿ ɜ ɛɚɡɢɫɧɿɣ ab- ɩɥɨɳɢɧɿ ɹɤ ɧɚɫɥɿɞɨɤ ʀɯ ɤɜɚɡɿɲɚɪɭɜɚɬɨʀ ɫɬɪɭɤɬɭɪɢ ɿ ɦɚɥɨɝɨ ɡɧɚɱɟɧɧɹ ɞɨɜɠɢɧɢ ɤɨɝɟɪɟɧɬɧɨɫɬɿ [1-5]. ɉɪɢ ɰɶɨɦɭ, ɡɦɿɧɚ ɜɦɿɫɬɭ ɤɢɫɧɸ ɬɚ ɥɟɝɭɜɚɧɧɹ ɞɨɦɿɲɤɚɦɢ ɿɫɬɨɬɧɨ ɜɩɥɢɜɚɽ ɧɚ ɩɪɨɰɟɫɢ ɮɨɪɦɭɜɚɧɧɹ ɮɥɭɤɬɭɚɰɿɣɧɢɯ ɤɭɩɟɪɿɜɫɶɤɢɯ ɩɚɪ ɿ, ɜɿɞɩɨɜɿɞɧɨ, ɪɟɚɥɿɡɚɰɿɸ ɪɿɡɧɢɯ ɪɟɠɢɦɿɜ ɿɫɧɭɜɚɧɧɹ ɮɥɭɤɬɭɚɰɿɣɧɨʀ ɩɪɨɜɿɞɧɨɫɬɿ (Ɏɉ) ɩɪɢ ɬɟɦɩɟɪɚɬɭɪɚɯ ɜɢɳɟ ɤɪɢɬɢɱɧɨʀ (Ɍɫ) [6,7]. ɇɚɣɛɿɥɶɲ ɜɢɜɱɟɧɨɸ, ɜ ɰɶɨɦɭ ɚɫɩɟɤɬɿ, ɽ ɫɩɨɥɭɤɚ YBa2Cu3O7-į, ɳɨ ɡɭɦɨɜɥɟɧɨ ɞɨɫɬɚɬɧɶɨ ɜɿɞɩɪɚɰɶɨɜɚɧɨɸ ɬɟɯɧɨɥɨɝɿɽɸ ɫɢɧɬɟɡɭ ɿ ɜɿɞɧɨɫɧɨɸ ɩɪɨɫɬɨɬɨɸ ɡɚɦɿɧɢ ɫɤɥɚɞɨɜɢɯ ɰɶɨɝɨ ɧɚɞɩɪɨɜɿɞɧɢɤɚ ʀɯ ɿɡɨɟɥɟɤɬɪɨɧɧɢɦɢ ɚɧɚɥɨɝɚɦɢ. ɐɟ, ɜ ɫɜɨɸ ɱɟɪɝɭ, ɜɿɞɤɪɢɜɚɽ ɧɚɦ ɲɥɹɯ ɞɥɹ ɦɨɞɟɥɸɜɚɧɧɹ ɩɪɨɜɿɞɧɢɯ ɯɚɪɚɤɬɟɪɢɫɬɢɤ ɿ ɜɢɡɧɚɱɟɧɧɹ ɟɦɩɿɪɢɱɧɢɯ ɲɥɹɯɿɜ ɩɿɞɜɢɳɟɧɧɹ ɤɪɢɬɢɱɧɢɯ ɩɚɪɚɦɟɬɪɿɜ ȼɌɇɉ. Ɉɫɨɛɥɢɜɭ ɰɿɤɚɜɿɫɬɶ ɜ ɰɶɨɦɭ ɚɫɩɟɤɬɿ ɩɪɟɞɫɬɚɜɥɹɽ ɱɚɫɬɤɨɜɚ ɡɚɦɿɧɚ Cu ɧɚ Al, ɤɨɬɪɚ ɩɪɢɜɨɞɢɬɶ ɞɨ ɜɿɞɫɭɬɧɨɫɬɿ «ɜɿɹɥɨɩɨɞɿɛɧɨɝɨ» ɪɨɡɲɢɪɟɧɧɹ ɪɟɡɢɫɬɢɜɧɨɝɨ ɩɟɪɟɯɨɞɭ ɜ ɧɚɞɩɪɨɜɿɞɧɢɣ ɫɬɚɧ [2-4], ɹɤɢɣ ɡɚɜɠɞɢ ɫɩɨɫɬɟɪɿɝɚɽɬɶɫɹ ɜ ɛɟɡɞɨɦɿɲɤɨɜɢɯ ɡɪɚɡɤɚɯ YBa2Cu3O7-į [8]. ɉɪɢɱɢɧɚ ɬɚɤɨʀ ɩɨɜɟɞɿɧɤɢ ɡɚɥɢɲɚɽɬɶɫɹ ɞɨɬɟɩɟɪ ɨɫɬɚɬɨɱɧɨ ɧɟɡ’ɹɫɨɜɚɧɨɸ. ɋɥɿɞ ɡɚɡɧɚɱɢɬɢ, ɳɨ ɩɟɪɟɪɚɯɨɜɚɧɿ ɨɫɨɛɥɢɜɨɫɬɿ ɩɨɜɢɧɧɿ ɿɫɬɨɬɧɨ ɜɩɥɢɜɚɬɢ ɧɚ ɪɟɚɥɿɡɚɰɿɸ ɪɟɠɢɦɭ ɮɥɭɤɬɭɚɰɿɣɧɨʀ ɧɚɞɩɪɨɜɿɞɧɨɫɬɿ, ɹɤɢɣ, ɹɤ ɞɨɛɪɟ ɜɿɞɨɦɨ, ɽ «ɩɟɪɟɞɜɿɫɧɢɤɨɦ» ɩɟɪɟɯɨɞɭ ɞɨ ɜɥɚɫɧɟ ɧɚɞɩɪɨɜɿɞɧɨɝɨ ɫɬɚɧɨɜɢɳɚ [6,9-11]. Ɂ ɭɪɚɯɭɜɚɧɧɹɦ ɜɢɳɟɫɤɚɡɚɧɨɝɨ, ɜ ɪɨɛɨɬɿ ɛɭɥɚ ɩɨɫɬɚɜɥɟɧɚ ɦɟɬɚ ɞɨɫɥɿɞɠɟɧɧɹ ɜɩɥɢɜɭ ɩɨɫɬɿɣɧɨɝɨ ɦɚɝɧɿɬɧɨɝɨ ɩɨɥɹ ɞɨ 12,7 ɤȿ ɩɪɢ ɨɪɿɽɧɬɚɰɿʀ ɇ __ɫ ɧɚ ɮɥɭɤɬɭɚɰɿɣɧɭ ɩɪɨɜɿɞɧɿɫɬɶ ɦɨɧɨɤɪɢɫɬɚɥɿɜ YBa2Cu3-zAlzO7-į (z”0,5) ɡ ɨɞɧɨɫɩɪɹɦɨɜɚɧɨɸ ɫɢɫɬɟɦɨɸ ɩɥɨɳɢɧɧɢɯ ɞɟɮɟɤɬɿɜ, ɹɤɚ ɞɨɡɜɨɥɹɥɚ ɜɿɞɩɨɜɿɞɧɢɦ ɱɢɧɨɦ ɪɟɝɭɥɸɜɚɬɢ ɩɪɨɰɟɫɢ ɪɨɡɫɿɸɜɚɧɧɹ ɧɨɫɿʀɜ ɫɬɪɭɦɭ. ɆȺɌȿɊȱȺɅɂ ȱ ȿɄɋɉȿɊɂɆȿɇɌȺɅɖɇȱ ɆȿɌɈȾɂɄɂ Ɇɨɧɨɤɪɢɫɬɚɥɢ YBa2Cu3-zAlzO7-į ɜɢɪɨɳɭɜɚɥɢ ɪɨɡɱɢɧ-ɪɨɡɩɥɚɜɧɢɦ ɦɟɬɨɞɨɦ ɜ ɡɨɥɨɬɨɦɭ ɬɢɝɥɿ ɩɪɢ ɫɥɚɛɤɨɦɭ ɩɨɡɞɨɜɠɧɶɨɦɭ ɝɪɚɞɿɽɧɬɿ ɬɟɦɩɟɪɚɬɭɪɢ ɡɝɿɞɧɨ ɦɟɬɨɞɢɤɢ [2,5]. Ⱦɥɹ ɪɟɡɢɫɬɢɜɧɢɯ ɜɢɦɿɪɸɜɚɧɶ ɜɿɞɛɢɪɚɥɢɫɶ ɬɨɧɤɿ ɤɪɢɫɬɚɥɢ, ɹɤɿ ɦɚɥɢ ɞɿɥɹɧɤɢ ɡ ɨɞɧɨɫɩɪɹɦɨɜɚɧɢɦɢ ɩɥɨɳɢɧɧɢɦɢ ɞɟɮɟɤɬɚɦɢ – ɦɟɠɚɦɢ ɞɜɿɣɧɢɤɿɜ (“twin boundaries” – Ɍȼ) ɪɨɡɦɿɪɨɦ ɛɥɢɡɶɤɨ 0,5ɯ0,5 ɦɦ2 ɿ ɬɨɜɳɢɧɨɸ 0,04 ɦɦ. ɐɟ ɞɨɡɜɨɥɹɥɨ ɜɢɪɿɡɚɬɢ ɡ ɬɚɤɢɯ ɦɨɧɨɤɪɢɫɬɚɥɿɜ ɦɿɫɬɤɢ ɡ ɨɞɧɨɫɩɪɹɦɨɜɚɧɢɦɢ Ɍȼ ɲɢɪɢɧɨɸ 0,2 ɦɦ ɿ ɜɿɞɫɬɚɧɧɸ ɦɿɠ ɩɨɬɟɧɰɿɣɧɢɦɢ ɤɨɧɬɚɤɬɚɦɢ 0,3 ɦɦ. ɉɪɢ ɰɶɨɦɭ ɦɿɫɬɨɤ ɜɢɪɿɡɚɥɢ ɬɚɤɢɦ ɱɢɧɨɦ, ɳɨɛ ɜɟɤɬɨɪ ɬɪɚɧɫɩɨɪɬɧɨɝɨ ɫɬɪɭɦɭ Iab ɛɭɜ ɩɚɪɚɥɟɥɶɧɢɦ ɩɥɨɳɢɧɚɦ ɞɜɿɣɧɢɤɿɜ, ɹɤ ɰɟ ɫɯɟɦɚɬɢɱɧɨ ɡɨɛɪɚɠɟɧɨ ɧɚ ɜɫɬɚɜɰɿ (ɚ) ɞɨ ɪɢɫ. 1. Ɇɟɬɨɞɢɤɚ ɜɢɝɨɬɨɜɥɟɧɧɹ ɟɤɫɩɟɪɢɦɟɧɬɚɥɶɧɢɯ ɡɪɚɡɤɿɜ ɿ ɫɬɜɨɪɟɧɧɹ ɟɥɟɤɬɪɨɤɨɧɬɚɤɬɿɜ ɛɿɥɶɲ ɞɟɬɚɥɶɧɨ ɨɩɢɫɚɧɚ ɜ [2,5]. Ɇɚɝɧɿɬɧɟ ɩɨɥɟ ɞɨ 12,7 ɤȿ ɫɬɜɨɪɸɜɚɥɢ ɟɥɟɤɬɪɨɦɚɝɧɿɬɨɦ. Ɉɛɟɪɬɚɧɧɹɦ ɦɚɝɧɿɬɭ ɦɨɠɧɚ ɛɭɥɨ ɡɦɿɧɸɜɚɬɢ ɨɪɿɽɧɬɚɰɿɸ ɩɨɥɹ ɜɿɞɧɨɫɧɨ ɤɪɢɫɬɚɥɚ. Ɍɨɱɧɿɫɬɶ ɨɪɿɽɧɬɚɰɿʀ ɩɨɥɹ ɳɨɞɨ ɡɪɚɡɤɚ ɛɭɥɚ ɧɟ ɝɿɪɲɚ 0,2°. Ɇɿɫɬɨɤ ɦɨɧɬɭɜɚɜɫɹ ɭ ɜɢɦɿɪɸɜɚɥɶɧɨɦɭ ɨɫɟɪɟɞɤɭ ɬɚɤ, ɳɨɛ ɜɟɤɬɨɪ ɩɨɥɹ ɇ ɡɚɜɠɞɢ ɛɭɜ ɩɟɪɩɟɧɞɢɤɭɥɹɪɧɢɣ ɜɟɤɬɨɪɭ ɬɪɚɧɫɩɨɪɬɧɨɝɨ ɫɬɪɭɦɭ. Ɍɨɱɧɿɫɬɶ ɜɢɦɿɪɸɜɚɧɧɹ ɬɟɦɩɟɪɚɬɭɪɢ ɫɤɥɚɞɚɥɚ 0,005 Ʉ. ɊȿɁɍɅɖɌȺɌɂ ȱ ɈȻȽɈȼɈɊȿɇɇə Ɍɟɦɩɟɪɚɬɭɪɧɿ ɡɚɥɟɠɧɨɫɬɿ ɩɢɬɨɦɨɝɨ ɟɥɟɤɬɪɨɨɩɨɪɭ ɜ ab-ɩɥɨɳɢɧɿ Uab(T) ɦɨɧɨɤɪɢɫɬɚɥɚ YBa2Cu3-zAlzO7-į ɩɪɢ ɪɿɡɧɢɯ ɦɚɝɧɿɬɧɢɯ ɩɨɥɹɯ ɩɪɟɞɫɬɚɜɥɟɧɿ ɧɚ ɪɢɫ.1. Ɋɟɡɢɫɬɢɜɧɿ ɩɟɪɟɯɨɞɢ ɜ ɧɚɞɩɪɨɜɿɞɧɢɣ ɫɬɚɧ ɰɶɨɝɨ ɠ ɡɪɚɡɤɚ ɜ ɤɨɨɪɞɢɧɚɬɚɯ ȡab - T ɿ dȡab/dT – T ɩɨɤɚɡɚɧɿ ɧɚ ɪɢɫ.2. Ʉɪɢɬɢɱɧɚ ɬɟɦɩɟɪɚɬɭɪɚ ɤɪɢɫɬɚɥɚ ɜ ɧɭɥɶɨɜɨɦɭ ɦɚɝɧɿɬɧɨɦɭ

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«Â³ñíèê Õàðê³âñüêîãî óí³âåðñèòåòó», ¹ 763, 2007

Ð.Â. Âîâê

ɩɨɥɿ, ɳɨ ɜɢɡɧɚɱɚɥɚɫɹ ɩɨ ɬɨɱɰɿ ɦɚɤɫɢɦɭɦɭ ɧɚ ɡɚɥɟɠɧɨɫɬɿ dȡab(Ɍ)/dT ɭ ɨɛɥɚɫɬɿ ɪɟɡɢɫɬɢɜɧɨɝɨ ɩɟɪɟɯɨɞɭ ɜ ɧɚɞɩɪɨɜɿɞɧɢɣ ɫɬɚɧ ɡɝɿɞɧɨ ɦɟɬɨɞɢɤɢ [6], ɞɨɪɿɜɧɸɜɚɥɚ 92,1 Ʉ ɩɪɢ ɲɢɪɢɧɿ ɩɟɪɟɯɨɞɭ ǻɌɫ”0,5 Ʉ. ɉɢɬɨɦɢɣ ɟɥɟɤɬɪɨɨɩɿɪ ɜ ab-ɩɥɨɳɢɧɿ ɩɪɢ ɤɿɦɧɚɬɧɿɣ ɬɟɦɩɟɪɚɬɭɪɿ ɫɤɥɚɞɚɜ ɛɥɢɡɶɤɨ 420 ɦɤɈɦ·ɫɦ. Ɂɝɿɞɧɨ ɥɿɬɟɪɚɬɭɪɧɢɯ ɞɚɧɢɯ, ɜɢɫɨɤɿ ɡɧɚɱɟɧɧɹ ɤɪɢɬɢɱɧɨʀ ɬɟɦɩɟɪɚɬɭɪɢ Ɍɫ § 92 Ʉ ɜɿɞɩɨɜɿɞɚɸɬɶ ɤɨɧɰɟɧɬɪɚɰɿʀ ɚɥɸɦɿɧɿɸ ɜ ɤɪɢɫɬɚɥɿ z d 0,05 [1-4] ɿ ɤɨɧɰɟɧɬɪɚɰɿʀ ɤɢɫɧɸ į d 0,1 [7]. ȼ ɬɨɣ ɠɟ ɱɚɫ, ɜɭɡɶɤɚ ɲɢɪɢɧɚ ɩɟɪɟɯɨɞɭ ɜ ɧɚɞɩɪɨɜɿɞɧɢɣ ɫɬɚɧ ǻɌɫ”0,5 Ʉ ɫɜɿɞɱɢɬɶ ɩɪɨ ɪɿɜɧɨɦɿɪɧɢɣ ɪɨɡɩɨɞɿɥ ɤɢɫɧɸ ɿ Al ɜ ɨɛ’ɽɦɿ ɤɪɢɫɬɚɥɭ.
Tc, K

2,5x10

-4

92

90

Uab, Ohm.cm

2,0x10

-4

1' 1'-6'
-1

1,0x10

-4

2,5x10

-4

88 0 2 4 6 8 10 12 14

Uab, Ohm.cm

1,5x10

Uab, Ohm.cm

-4

5,0x10

-5

2,0x10

-4

H, kE

4,0x10

-5

6
1,5x10
-4

5

4

3

2 2' 3'

1

dUab/dT, Ohm.cm.K

8,0x10

-5

1,0x10

-4

c

(a)

3,0x10

-5

(b)
HIIc H=O

6,0x10

-5

H
5,0x10
-5

1-6
1,0x10
-4

2,0x10

-5

TB
6 1 b(a)

Iab

a(b)

1,0x10

-5

6'
0,0

5'

4'

4,0x10

-5

87

88

89

90

91

92

93

94

95

0,0

T, K

5,0x10

-5

2,0x10

-5

100

125

150

0,0

0,0

T, K

86

88

90

92

T, K

Ɋɢɫ. 1. Ɍɟɦɩɟɪɚɬɭɪɧɿ ɡɚɥɟɠɧɨɫɬɿ ɟɥɟɤɬɪɨɨɩɨɪɭ ȡab(T) Ɋɢɫ. 2. ɉɟɪɟɯɨɞɢ ɜ ɧɚɞɩɪɨɜɿɞɧɢɣ ɫɬɚɧ ɦɨɧɨɤɪɢɫɬɚɥɚ ɦɨɧɨɤɪɢɫɬɚɥɚ YBa2Cu3-zAlzO7-į ɞɥɹ ɇ=0; 1,9; 4,5; 7,3; 10; 12,7 ɤȿ, YBa2Cu3-zAlzO7-į ɩɪɢ ɪɿɡɧɢɯ ɡɧɚɱɟɧɧɹɯ ɦɚɝɧɿɬɧɨɝɨ ɩɨɥɹ ɜ ɤɨɨɪɞɢɧɚɬɚɯ ȡab – Ɍ ɿ dȡab/dT – T – T, ɤɪɢɜɿ 1 - 6, ɜɿɞɩɨɜɿɞɧɨ. ɉɭɧɤɬɢɪɧɨɸ ɥɿɧɿɽɸ ɩɨɤɚɡɚɧɚ ɟɤɫɬɪɚɩɨɥɹɰɿɹ ɥɿɧɿɣɧɨʀ ɞɿɥɹɧɤɢ ɤɪɢɜɿ 1-6 ɿ 1’-6’, ɜɿɞɩɨɜɿɞɧɨ. ɟɤɫɩɟɪɢɦɟɧɬɚɥɶɧɨʀ ɡɚɥɟɠɧɨɫɬɿ. ɇɭɦɟɪɚɰɿɹ ɤɪɢɜɢɯ ɜɿɞɩɨɜɿɞɚɽ ɧɭɦɟɪɚɰɿʀ ɧɚ ɪɢɫ. 1. ɇɚ ɜɫɬɚɜɰɿ (ɚ) ɩɨɤɚɡɚɧɟ ɫɯɟɦɚɬɢɱɧɟ ɡɨɛɪɚɠɟɧɧɹ ɝɟɨɦɟɬɪɿʀɇɚ ɜɫɬɚɜɰɿ ɩɨɤɚɡɚɧɚ ɩɨɥɶɨɜɚ ɡɚɥɟɠɧɿɫɬɶ ɤɪɢɬɢɱɧɨʀ ɟɤɫɩɟɪɢɦɟɧɬɭ. ȼɫɬɚɜɤɚ (b): ɫɯɟɦɚɬɢɱɧɟ ɡɨɛɪɚɠɟɧɧɹ ɪɨɡɲɢɪɟɧɧɹɬɟɦɩɟɪɚɬɭɪɢ Ɍɫ(ɇ). ɪɟɡɢɫɬɢɜɧɨɝɨ ɩɟɪɟɯɨɞɭ ɜ ɧɚɞɩɪɨɜɿɞɧɢɣ ɫɬɚɧ ɜ ɦɚɝɧɿɬɧɨɦɭ ɩɨɥɿ ɇ __ɫ ɞɥɹ ɜɢɩɚɞɤɭ ɛɟɡɞɨɦɿɲɤɨɜɨʀ ɫɩɨɥɭɤɢ YBaCuO ɡɝɿɞɧɨ [8].

ɉɪɢ ɡɧɢɠɟɧɧɿ ɬɟɦɩɟɪɚɬɭɪɢ ɜɿɞ 300 ɞɨ 200 Ʉ ȡab(Ɍ) ɡɦɟɧɲɭɽɬɶɫɹ ɮɚɤɬɢɱɧɨ ɥɿɧɿɣɧɨ, ɳɨ ɜɤɚɡɭɽ ɧɚ ɤɜɚɡɿɦɟɬɚɥɟɜɭ ɩɨɜɟɞɿɧɤɭ ɩɪɨɜɿɞɧɨɫɬɿ ɜ ɰɶɨɦɭ ɬɟɦɩɟɪɚɬɭɪɧɨɦɭ ɿɧɬɟɪɜɚɥɿ. ɉɪɢ ɰɶɨɦɭ ɦɚɝɧɿɬɧɟ ɩɨɥɟ ɩɪɚɤɬɢɱɧɨ ɧɟ ɜɩɥɢɜɚɽ ɧɚ ɩɨɜɟɞɿɧɤɭ ɡɚɥɟɠɧɨɫɬɟɣ ȡab(Ɍ) ɩɪɢ Ɍ•1,15 Ɍɫ, ɳɨ ɭɡɝɨɞɠɭɽɬɶɫɹ ɡ ɥɿɬɟɪɚɬɭɪɧɢɦɢ ɞɚɧɢɦɢ ɞɥɹ ɱɢɫɬɢɯ ɡɪɚɡɤɿɜ YBaCuO [8]. əɤ ɜɿɞɡɧɚɱɚɥɨɫɹ ɜɢɳɟ, ɨɞɧɿɽɸ ɡ ɯɚɪɚɤɬɟɪɧɢɯ ɨɫɨɛɥɢɜɨɫɬɟɣ ɛɟɡɞɨɦɿɲɤɨɜɢɯ ɫɩɨɥɭɤ YBaCuO ɽ ɡɧɚɱɧɟ ɪɨɡɲɢɪɟɧɧɹ ɩɟɪɟɯɨɞɭ ɜ ɧɚɞɩɪɨɜɿɞɧɟ ɫɬɚɧɨɜɢɳɟ ɜ ɡɨɜɧɿɲɧɶɨɦɭ ɦɚɝɧɿɬɧɨɦɭ ɩɨɥɿ [8], ɹɤ ɰɟ ɫɯɟɦɚɬɢɱɧɨ ɩɨɤɚɡɚɧɨ ɧɚ ɜɫɬɚɜɰɿ ɞɨ ɪɢɫ.1. ɐɟ ɪɨɡɲɢɪɟɧɧɹ ɩɨɹɫɧɸɽɬɶɫɹ ɬɢɦ, ɳɨ ɜ ɦɚɝɧɿɬɧɢɯ ɩɨɥɹɯ ɦɟɧɲɢɯ ɞɪɭɝɨɝɨ ɤɪɢɬɢɱɧɨɝɨ ɇɫ2 ɿɫɧɭɽ ɜɢɯɨɪɨɜɚ ɪɿɞɢɧɚ, ɤɪɢɫɬɚɥɿɡɚɰɿɹ ɹɤɨʀ ɜ ɩɪɢɫɭɬɧɨɫɬɿ ɫɥɚɛɤɨɝɨ ɛɟɡɩɨɪɹɞɤɭ ɜɿɞɛɭɜɚɽɬɶɫɹ ɭ ɜɢɝɥɹɞɿ ɮɚɡɨɜɨɝɨ ɩɟɪɟɯɨɞɭ ɩɟɪɲɨɝɨ ɪɨɞɭ [2-5]. ȼ ɧɚɲɨɦɭ ɜɢɩɚɞɤɭ ɜɩɥɢɜ ɦɚɝɧɿɬɧɨɝɨ ɩɨɥɹ ɡɜɨɞɢɬɶɫɹ ɜ ɨɫɧɨɜɧɨɦɭ ɞɨ ɦɚɣɠɟ ɟɤɜɿɞɢɫɬɚɧɬɧɨɝɨ ɡɦɿɳɟɧɧɹ ɜɧɢɡ ɩɨ ɬɟɦɩɟɪɚɬɭɪɿ ɪɟɡɢɫɬɢɜɧɨɝɨ ɩɟɪɟɯɨɞɭ ɜ ɧɚɞɩɪɨɜɿɞɧɢɣ ɫɬɚɧ ɿ ɫɥɚɛɤɨɦɭ ɣɨɝɨ ɪɨɡɲɢɪɟɧɧɸ, ɩɪɨ ɳɨ ɞɟɬɚɥɶɧɿɲɟ ɛɭɞɟ ɫɤɚɡɚɧɨ ɧɢɠɱɟ . ɉɪɢ ɰɶɨɦɭ ɤɪɢɬɢɱɧɚ ɬɟɦɩɟɪɚɬɭɪɚ ɦɨɧɨɬɨɧɧɨ ɡɧɢɠɭɽɬɶɫɹ ɡ ɪɨɫɬɨɦ ɦɚɝɧɿɬɧɨɝɨ ɩɨɥɹ , ɹɤ ɰɟ ɜɢɞɧɨ ɡɿ ɜɫɬɚɜɤɢ ɞɨ ɪɢɫ . 2. ȼ ɬɨɣ ɠɟ ɱɚɫ , ɡɧɢɠɟɧɧɹ ɬɟɦɩɟɪɚɬɭɪɢ ɞɨ Ɍ ” 200 Ʉ ɩɪɢɜɨɞɢɬɶ ɞɨ ɜɿɞɯɢɥɟɧɧɹ Uab(Ɍ) ɜɿɞ ɥɿɧɿɣɧɨʀ ɡɚɥɟɠɧɨɫɬɿ, ɳɨ ɫɜɿɞɱɢɬɶ ɩɪɨ ɩɨɹɜɭ ɞɟɹɤɨʀ ɧɚɞɥɢɲɤɨɜɨʀ ɩɪɨɜɿɞɧɨɫɬɿ, ɬɟɦɩɟɪɚɬɭɪɧɚ ɡɚɥɟɠɧɿɫɬɶ ɹɤɨʀ ɡɚɡɜɢɱɚɣ ɜɢɡɧɚɱɚɽɬɶɫɹ ɡ ɪɿɜɧɹɧɧɹ:

'V

V V0 ,

(1)

ɞɟ V0=U01=(Ⱥ+ȼɌ)1 – ɩɪɨɜɿɞɧɿɫɬɶ, ɳɨ ɜɢɡɧɚɱɚɽɬɶɫɹ ɟɤɫɬɪɚɩɨɥɹɰɿɽɸ ɥɿɧɿɣɧɨʀ ɞɿɥɹɧɤɢ ɜ ɧɭɥɶɨɜɟ ɡɧɚɱɟɧɧɹ ɬɟɦɩɟɪɚɬɭɪɢ, ɚ V=U1 – ɟɤɫɩɟɪɢɦɟɧɬɚɥɶɧɟ ɡɧɚɱɟɧɧɹ ɩɪɨɜɿɞɧɨɫɬɿ ɭ ɧɨɪɦɚɥɶɧɨɦɭ ɫɬɚɧɿ. Ɂ ɬɟɨɪɿʀ [9] ɜɿɞɨɦɨ, ɳɨ ɩɨɛɥɢɡɭ Ɍɫ ɧɚɞɥɢɲɤɨɜɚ ɩɪɨɜɿɞɧɿɫɬɶ ɡɭɦɨɜɥɟɧɚ ɩɪɨɰɟɫɚɦɢ ɮɥɭɤɬɭɚɰɿɣɧɨɝɨ ɫɩɚɪɨɜɭɜɚɧɧɹ ɧɨɫɿʀɜ, ɜɧɟɫɨɤ ɹɤɢɯ ɜ ɩɪɨɜɿɞɧɿɫɬɶ ɩɪɢ Ɍ>Ɍɫ ɞɥɹ ɞɜɨɯ (2D) ɿ ɬɪɢɜɢɦɿɪɧɨɝɨ (3D) ɜɢɩɚɞɤɿɜ ɜɢɡɧɚɱɚɽɬɶɫɹ ɫɬɭɩɟɧɟɜɢɦɢ ɡɚɥɟɠɧɨɫɬɹɦɢ ɜɢɞɭ:

'V 2 D 'V 3 D

e 2 1 H , 16=d e2 H 1 / 2 , 32=[ c (0)

(2) (3)

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ñåð³ÿ ô³çè÷íà «ßäðà, ÷àñòèíêè, ïîëÿ», âèï. 1 /33/

Âïëèâ ïîïåðå÷íîãî ìàãí³òíîãî ïîëÿ íà...

ɞɟ H=(T-Tc)/Tc, ɟ – ɡɚɪɹɞ ɟɥɟɤɬɪɨɧɚ, [ɫ(0)  ɞɨɜɠɢɧɚ ɤɨɝɟɪɟɧɬɧɨɫɬɿ ɜɡɞɨɜɠ ɨɫɿ ɫ ɩɪɢ Ɍ>0 ɿ d  ɯɚɪɚɤɬɟɪɧɢɣ ɪɨɡɦɿɪ ɞɜɨɜɢɦɿɪɧɨɝɨ ɲɚɪɭ.

9,6 9,4 9,2 9,0 8,8 8,6 8,4 8,2 6 5 4 3

'V

2

1

2,40 2,38 2,36

(b)
88 90 8,5 8,0 92

T, K
6

[c(0), A

2,34 2,32 2,30 2,28 2,26 2,24 0 1 2 3 4 5 6 ln'V

3D
7,5 7,0 6,5 -3

1

(a)
2D
-2

ln H

-1

7

8

9

10

11

12

13

14

H , kE
Ɋɢɫ. 3. ɉɨɥɶɨɜɚ ɡɚɥɟɠɧɿɫɬɶ ɞɨɜɠɢɧɢ ɤɨɝɟɪɟɧɬɧɨɫɬɿ ɩɟɪɩɟɧɞɢɤɭɥɹɪɧɨ ɛɚɡɢɫɧɿɣ ɩɥɨɳɢɧɿ [ɫ(0,ɇ). ȼɫɬɚɜɤɢ (ɚ) ɿ (b): ɬɟɦɩɟɪɚɬɭɪɧɿ ɡɚɥɟɠɧɨɫɬɿ ɧɚɞɥɢɲɤɨɜɨʀ ɩɪɨɜɿɞɧɨɫɬɿ ɜ ab-ɩɥɨɳɢɧɿ ɜ ɤɨɨɪɞɢɧɚɬɚɯ lnǻV-lnH ɿ lnǻV-Ɍ ɩɪɢ ɪɿɡɧɢɯ ɡɧɚɱɟɧɧɹɯ ɦɚɝɧɿɬɧɨɝɨ ɩɨɥɹ. ɉɨɡɧɚɱɟɧɧɹ ɤɪɢɜɢɯ ɧɚ ɜɫɬɚɜɤɚɯ ɜɿɞɩɨɜɿɞɚɽ ɩɨɡɧɚɱɟɧɧɹɦ ɧɚ ɪɢɫ. 1. ɉɭɧɤɬɢɪɧɢɦɢ ɥɿɧɿɹɦɢ ɧɚ ɜɫɬɚɜɰɿ (ɚ) ɩɨɤɚɡɚɧɚ ɚɩɪɨɤɫɢɦɚɰɿɹ ɟɤɫɩɟɪɢɦɟɧɬɚɥɶɧɢɯ ɡɚɥɟɠɧɨɫɬɟɣ ɩɪɹɦɢɦɢ ɡ ɤɭɬɨɦ ɧɚɯɢɥɭ tgĮ1§-0,5 (3D - ɪɟɠɢɦ) ɿ tgĮ1§-1,0 (2D - ɪɟɠɢɦ). ɋɬɪɿɥɤɚɦɢ ɩɨɤɚɡɚɧɿ ɬɨɱɤɢ 2D-3D ɤɪɨɫɨɜɟɪɚ. ɉɭɧɤɬɢɪɧɨɸ ɥɿɧɿɽɸ ɧɚ ɜɫɬɚɜɰɿ (b) ɩɨɤɚɡɚɧɚ ɟɤɫɬɪɚɩɨɥɹɰɿɹ ɥɿɧɿɣɧɨʀ ɞɿɥɹɧɤɢ ɡɚɥɟɠɧɨɫɬɿ lnǻV-Ɍ. ɋɬɪɿɥɤɚɦɢ ɩɨɤɚɡɚɧɿ ɬɨɱɤɢ ɩɟɪɟɯɨɞɭ ɞɨ Ɏɉ-ɪɟɠɢɦɭ.

ɇɚ ɜɫɬɚɜɰɿ (ɚ) ɞɨ ɪɢɫ.3 ɩɨɤɚɡɚɧɿ ɬɟɦɩɟɪɚɬɭɪɧɿ ɡɚɥɟɠɧɨɫɬɿ ǻV(Ɍ) ɭ ɤɨɨɪɞɢɧɚɬɚɯ lnǻV - lnH. ȼɢɞɧɨ, ɳɨ ɩɨɛɥɢɡɭ Ɍɫ ɰɿ ɡɚɥɟɠɧɨɫɬɿ ɡɚɞɨɜɿɥɶɧɨ ɚɩɪɨɤɫɢɦɭɸɬɶɫɹ ɩɪɹɦɢɦɢ ɡ ɤɭɬɨɦ ɧɚɯɢɥɭ tgĮ1§-0,5, ɹɤɢɣ ɜɿɞɩɨɜɿɞɚɽ ɩɨɤɚɡɧɢɤɭ ɫɬɭɩɟɧɹ -1/2 ɜ ɪɿɜɧɹɧɧɿ (4), ɳɨ, ɨɱɟɜɢɞɧɨ, ɫɜɿɞɱɢɬɶ ɩɪɨ ɬɪɢɜɢɦɿɪɧɢɣ ɯɚɪɚɤɬɟɪ ɮɥɭɤɬɭɚɰɿɣɧɨʀ ɧɚɞɩɪɨɜɿɞɧɨɫɬɿ ɜ ɰɶɨɦɭ ɬɟɦɩɟɪɚɬɭɪɧɨɦɭ ɿɧɬɟɪɜɚɥɿ. ɉɪɢ ɩɨɞɚɥɶɲɨɦɭ ɩɿɞɜɢɳɟɧɧɿ ɬɟɦɩɟɪɚɬɭɪɢ ɲɜɢɞɤɿɫɬɶ ɡɦɟɧɲɟɧɧɹ ǻV ɿɫɬɨɬɧɨ ɡɪɨɫɬɚɽ (tgĮ2§-1), ɳɨ, ɭ ɫɜɨɸ ɱɟɪɝɭ, ɦɨɠɧɚ ɪɨɡɝɥɹɞɚɬɢ ɹɤ ɜɤɚɡɿɜɤɭ ɧɚ ɡɦɿɧɭ ɜɢɦɿɪɧɨɫɬɿ ɮɥɭɤɬɭɚɰɿɣɧɨʀ ɩɪɨɜɿɞɧɨɫɬɿ. əɤ ɛɭɥɨ ɩɨɤɚɡɚɧɨ ɜ ɪɨɛɨɬɿ [10], ɡɚɝɚɥɶɧɢɣ ɜɢɪɚɡ ɞɥɹ ɮɥɭɤɬɭɚɰɿɣɧɨʀ ɩɚɪɚɩɪɨɜɿɞɧɨɫɬɿ ǻV(Ɍ,ɇ) ɲɚɪɭɜɚɬɢɯ ɧɚɞɩɪɨɜɿɞɧɢɤɿɜ ɜ ɦɚɝɧɿɬɧɨɦɭ ɩɨɥɿ ɦɨɠɟ ɛɭɬɢ ɡɚɩɢɫɚɧɨ ɭ ɜɢɝɥɹɞɿ:

'V (T , H )
ɞɟ

'V AL (T , H )  'V MT (T , H ) ,

(4)

'V AL (T , H )

e2 16=dH

­ ½ 1 (2  4D  3D 2 ) b 2  ...¾  ® 1/ 2 5/ 2 2 4(1  2D ) H ¯ (1  2D ) ¿

(5)

ɮɥɭɤɬɭɚɰɿɣɧɚ ɩɪɨɜɿɞɧɿɫɬɶ Ⱥɫɥɚɦɚɡɨɜɚ- Ʌɚɪɤɿɧɚ [9];

½ ­ G 1  D  1  2D b2 G 2 1 G 1D ) [ 2 ]  ...¾  (6) ®ln( 3/ 2 3/ 2 6H D (1  2G ) (1  2D ) ¿ ¯ D 1  G  1  2G ɮɥɭɤɬɭɚɰɿɣɧɚ ɩɪɨɜɿɞɧɿɫɬɶ Ɇɚɤɿ-Ɍɨɦɩɫɨɧɚ [11], ɡɭɦɨɜɥɟɧɚ ɜɡɚɽɦɨɞɿɽɸ ɧɟɫɩɚɪɨɜɚɧɢɯ ɧɨɫɿʀɜ ɫɬɪɭɦɭ ɡ 2 ɮɥɭɤɬɭɚɰɿɣɧɢɦɢ ɤɭɩɟɪɿɜɫɶɤɢɦɢ ɩɚɪɚɦɢ; D 2[ c2 (0) / d 2 H ; b (2e[ ab (0) / =H ; 'V MT (T , H ) e2 8=d (1  D / G )H

100
«Â³ñíèê Õàðê³âñüêîãî óí³âåðñèòåòó», ¹ 763, 2007

Ð.Â. Âîâê

G

(16 / S )([ c2 (0) / d 2 )(kTW M / = ) ; [ab(0) - ɞɨɜɠɢɧɚ ɤɨɝɟɪɟɧɬɧɨɫɬɿ ɜ ɛɚɡɢɫɧɿɣ ɩɥɨɳɢɧɿ, ɚ IJij – ɯɚɪɚɤɬɟɪɧɢɣ

ɬɟɪɦɿɧ ɡɛɨɸ ɩɚɪɚɦɟɬɪɚ ɩɨɪɹɞɤɭ. Ɋɟɲɬɚ ɩɨɡɧɚɱɟɧɶ ɬɚ ɠ, ɳɨ ɿ ɜ (2), (3). ɉɨɤɥɚɜɲɢ [ɫ(0) § 2,4 Å, d § 11,7 Å [12], IJij § ʄ/2k B T c , ɦɨɠɧɚ ɨɰɿɧɢɬɢ ɟɜɨɥɸɰɿɸ ɜɿɞɧɨɫɧɨɝɨ ɜɧɟɫɤɭ ɤɨɠɧɨʀ ɡ ɫɤɥɚɞɨɜɢɯ ɭ ɪɿɜɧɹɧɧɿ (4) ǻVAL/ǻVɆɌ ɭ ɦɿɪɭ ɜɿɞɞɚɥɟɧɧɹ ɜɝɨɪɭ ɩɨ ɬɟɦɩɟɪɚɬɭɪɿ ɜɿɞ ɬɨɱɤɢ ɩɟɪɟɯɨɞɭ ɜ ɧɚɞɩɪɨɜɿɞɧɢɣ ɫɬɚɧ ɜ ɧɭɥɶɨɜɨɦɭ ɦɚɝɧɿɬɧɨɦɭ ɩɨɥɿ , ɹɤ ɰɟ ɛɭɥɨ ɡɚɩɪɨɩɨɧɨɜɚɧɨ ɜ [13]. Ⱥɧɚɥɿɡ ɜɢɪɚɡɿɜ (5) ɿ (6) ɩɨɤɚɡɭɽ, ɳɨ ɯɨɱɚ ɜ ɿɧɬɟɪɜɚɥɿ ɬɟɦɩɟɪɚɬɭɪ Ɍɫ<Ɍ<1,25 Ɍɫ ɤɨɦɩɨɧɟɧɬɚ ǻVɆɌ(Ɍ, ɇ=0) ɜ ɩɨɪɿɜɧɹɧɧɿ ɡ ǻVAL(Ɍ, ɇ=0) ɡɧɚɱɧɨ ɫɥɚɛɤɿɲɟ ɡɚɥɟɠɢɬɶ ɜɿɞ ɬɟɦɩɟɪɚɬɭɪɢ, ɫɩɿɜɜɿɞɧɨɲɟɧɧɹ ǻVAL/ǻVɆɌ ɡɦɟɧɲɭɽɬɶɫɹ ɛɿɥɶɲɟ ɧɿɠ ɭɞɜɿɱɿ ɩɪɢ ɡɪɨɫɬɚɧɧɿ ɬɟɦɩɟɪɚɬɭɪɢ ɜɿɞ 1,005 Ɍ ɫ ɞɨ 1,25 Ɍ ɫ . ɐɟ, ɭ ɫɜɨɸ ɱɟɪɝɭ, ɦɨɠɟ ɫɜɿɞɱɢɬɢ ɩɪɨ ɡɧɚɱɧɟ ɡɪɨɫɬɚɧɧɹ ɿɧɬɟɧɫɢɜɧɨɫɬɿ ɪɨɡɫɿɸɜɚɧɧɹ ɤɭɩɟɪɿɜɫɶɤɢɯ ɩɚɪ ɧɨɪɦɚɥɶɧɢɦɢ ɧɨɫɿɹɦɢ. ɋɥɿɞ ɬɚɤɨɠ ɜɿɞɡɧɚɱɢɬɢ, ɳɨ, ɹɤ ɩɨɤɚɡɚɜ ɚɧɚɥɿɡ, ɜɫɿ ɨɬɪɢɦɚɧɿ ɡɚɥɟɠɧɨɫɬɿ ǻV(Ɍ,ɇ) ɭ ɿɧɬɟɪɜɚɥɿ ɬɟɦɩɟɪɚɬɭɪ 1,15 - 1,25 Ɍc ɡɚɞɨɜɿɥɶɧɨ ɚɩɪɨɤɫɢɦɭɸɬɶɫɹ ɡɚɥɟɠɧɿɫɬɸ (2), ɳɨ ɜɿɞɩɨɜɿɞɚɽ ɞɜɨɜɢɦɿɪɧɨɦɭ ɜɢɩɚɞɤɭ (ɜɫɬɚɜɤɚ (ɚ) ɞɨ ɪɢɫ.2), ɬɨɞɿ ɹɤ ɩɪɢ Ɍ < 1,1 Ɍɫ ɩɨɜɟɞɿɧɤɚ ǻV(Ɍ,ɇ) ɞɨɛɪɟ ɜɿɞɩɨɜɿɞɚɽ ɡɚɥɟɠɧɨɫɬɿ (3) ɞɥɹ ɬɪɢɜɢɦɿɪɧɨɝɨ ɜɢɩɚɞɤɭ. əɤ ɜɢɩɥɢɜɚɽ ɡ (2) ɿ (3), ɜ ɬɨɱɰɿ 2D-3D ɤɪɨɫɨɜɟɪɚ:

[ c (0)H 0 1 / 2

d /2.

(7)

ȼ ɰɶɨɦɭ ɜɢɩɚɞɤɭ, ɜɢɡɧɚɱɢɜɲɢ ɜɟɥɢɱɢɧɭ İ0 ɜ ɬɨɱɰɿ ɩɟɪɟɬɢɧɭ ɞɜɨɯ ɩɪɹɦɢɯ, ɳɨ ɜɿɞɩɨɜɿɞɚɸɬɶ ɩɨɤɚɡɧɢɤɚɦ ɫɬɭɩɟɧɹ –0,5 ɿ -1 ɧɚ ɡɚɥɟɠɧɨɫɬɹɯ lnǻV - lnH ɿ ɜɢɤɨɪɢɫɬɨɜɭɸɱɢ ɥɿɬɟɪɚɬɭɪɧɿ ɞɚɧɿ ɩɪɨ ɡɚɥɟɠɧɿɫɬɶ ɦɿɠɩɥɨɳɢɧɧɨʀ ɜɿɞɫɬɚɧɿ ɜɿɞ į [12] (d § 11,7 Å), ɦɨɠɧɚ ɨɛɱɢɫɥɢɬɢ ɡɧɚɱɟɧɧɹ [ɫ(0). ȱɡ ɜɫɬɚɜɤɢ ɞɨ ɪɢɫ.2, ɧɚ ɹɤɿɣ ɩɨɤɚɡɚɧɚ ɩɨɥɶɨɜɚ ɡɚɥɟɠɧɿɫɬɶ [ɫ(0,ɇ), ɜɢɞɧɨ, ɳɨ ɤɪɢɜɚ [ɫ(0,ɇ) ɯɚɪɚɤɬɟɪɢɡɭɽɬɶɫɹ ɹɫɤɪɚɜɨ ɜɢɪɚɠɟɧɢɦ ɦɚɤɫɢɦɭɦɨɦ ɭ ɨɛɥɚɫɬɿ ɦɚɝɧɿɬɧɢɯ ɩɨɥɿɜ ɇ § 2 ɤȿ . Ƀɦɨɜɿɪɧɨ , ɰɹ ɨɫɨɛɥɢɜɿɫɬɶ ɦɨɠɟ ɛɭɬɢ ɩɨɜ ' ɹɡɚɧɚ ɡ ɞɟɹɤɢɦ ɩɪɢɝɧɿɱɟɧɧɹɦ ɧɚɞɥɢɲɤɨɜɨʀ ɮɥɭɤɬɭɚɰɿɣɧɨʀ ɩɪɨɜɿɞɧɨɫɬɿ ɩɪɢ ɩɨɫɢɥɟɧɧɿ ɞɢɫɢɩɚɰɿʀ , ɹɤ ɧɚɫɥɿɞɨɤ ɡɦɿɳɟɧɧɹ ɧɚɞɩɪɨɜɿɞɧɢɯ ɮɥɭɤɬɭɚɰɿɣ ɜ ɡɪɚɡɤɭ ɩɿɞ ɞɿɽɸ ɫɢɥɢ Ʌɨɪɟɧɰɚ. ɍ ɫɜɨɸ ɱɟɪɝɭ, ɡɦɟɧɲɟɧɧɹ ǻV, ɡɝɿɞɧɨ (3), ɩɨɜɢɧɧɨ ɩɪɢɜɨɞɢɬɢ ɞɨ ɡɪɨɫɬɚɧɧɹ ɜɟɥɢɱɢɧɢ [ɫ(0,ɇ), ɳɨ ɿ ɫɩɨɫɬɟɪɿɝɚɽɬɶɫɹ ɜ ɧɚɲɨɦɭ ɜɢɩɚɞɤɭ. ɉɪɢ ɩɨɞɚɥɶɲɨɦɭ ɡɛɿɥɶɲɟɧɧɿ ɩɨɥɹ ɣɨɝɨ ɜɩɥɢɜ ɜɢɹɜɥɹɬɢɦɟɬɶɫɹ ɜ ɡɦɟɧɲɟɧɧɿ ɤɨɪɟɥɹɰɿɣɧɨʀ ɮɭɧɤɰɿʀ ɮɥɭɤɬɭɚɰɿɣ , ɳɨ ɩɨɜɢɧɧɨ ɩɨɡɧɚɱɢɬɢɫɹ ɧɚ ɫɢɥɿ ɩɿɧɧɿɧɝɭ ɮɥɭɤɬɭɚɰɿɣ [14] ɿ ɡɛɿɥɶɲɟɧɧɿ ɝɪɚɞɿɽɧɬɚ ɯɚɪɚɤɬɟɪɧɨʀ ɨɛ'ɽɦɧɨʀ ɝɭɫɬɢɧɢ ɮɥɭɤɬɭɚɰɿɣɧɨʀ ɟɧɟɪɝɿʀ. ȼ ɰɶɨɦɭ ɜɢɩɚɞɤɭ ɡɪɨɫɬɚɧɧɹ ɜɟɥɢɱɢɧɢ [ɫ(0,ɇ) ɡɦɿɧɢɬɶɫɹ ʀʀ ɡɦɟɧɲɟɧɧɹɦ. ɋɥɿɞ ɬɚɤɨɠ ɜɿɞɡɧɚɱɢɬɢ, ɳɨ ɹɤɳɨ ɜɢɡɧɚɱɚɬɢ ɬɟɦɩɟɪɚɬɭɪɭ ɩɟɪɟɯɨɞɭ ɜ Ɏɉ-ɪɟɠɢɦ Ɍf ɩɨ ɬɨɱɰɿ ɜɿɞɯɢɥɟɧɧɹ ɜɟɥɢɱɢɧɢ lnǻV ɜɝɨɪɭ ɜɿɞ ɥɿɧɿɣɧɨʀ ɡɚɥɟɠɧɨɫɬɿ lnǻV(T) [15] (ɞɢɜ. ɜɫɬɚɜɤɭ (b) ɞɨ ɪɢɫ.3), ɦɨɠɧɚ ɨɰɿɧɢɬɢ ɜɿɞɧɨɫɧɭ ɩɪɨɬɹɠɧɿɫɬɶ ɿɫɧɭɜɚɧɧɹ Ɏɉ -ɪɟɠɢɦɭ ɹɤ: tf=(Ɍf-Tc)/Tc. Ɋɟɡɭɥɶɬɚɬɢ ɪɨɡɪɚɯɭɧɤɿɜ ɩɨɤɚɡɭɸɬɶ, ɳɨ ɩɿɞ ɜɩɥɢɜɨɦ ɦɚɝɧɿɬɧɨɝɨ ɩɨɥɹ ɜɿɞɛɭɜɚɽɬɶɫɹ ɡɚɝɚɥɶɧɟ ɜɿɞɧɨɫɧɟ ɡɜɭɠɟɧɧɹ ɬɟɦɩɟɪɚɬɭɪɧɨɝɨ ɿɧɬɟɪɜɚɥɭ, ɜ ɹɤɨɦɭ ɪɟɚɥɿɡɭɽɬɶɫɹ ɪɟɠɢɦ ɮɥɭɤɬɭɚɰɿɣɧɨʀ ɩɚɪɚɩɪɨɜɿɞɧɨɫɬɿ ɜɿɞ tf § 0,1594 ɜ ɧɭɥɶɨɜɨɦɭ ɦɚɝɧɿɬɧɨɦɭ ɩɨɥɿ ɞɨ tf § 0,1473 ɩɪɢ ɇ=12,7 ɤȿ. ȼɿɪɨɝɿɞɧɨ, ɰɟ ɩɨɜ'ɹɡɚɧɨ ɡ ɩɪɢɝɧɿɱɟɧɧɹɦ ɩɪɢ ɡɪɨɫɬɚɧɧɿ ɦɚɝɧɿɬɧɨɝɨ ɩɨɥɹ ɞɨɜɝɨɯɜɢɥɶɨɜɢɯ ɮɥɭɤɬɭɚɰɿɣ, ɹɤɿ ɞɚɸɬɶ ɧɚɣɿɫɬɨɬɧɿɲɢɣ ɜɧɟɫɨɤ ɜ ɩɚɪɚɩɪɨɜɿɞɧɿɫɬɶ ɩɨɛɥɢɡɭ Ɍɫ. ȼ ɬɨɣ ɠɟ ɱɚɫ, ɹɤ ɛɭɥɨ ɩɨɤɚɡɚɧɨ ɜ [15], ɧɟɞɨɨɰɿɧɤɚ ɜɧɟɫɤɭ ɤɨɪɨɬɤɨɯɜɢɥɶɨɜɢɯ ɮɥɭɤɬɭɚɰɿɣ ɩɚɪɚɦɟɬɪɚ ɩɨɪɹɞɤɭ ɩɪɢɜɨɞɢɬɶ ɞɨ ɛɿɥɶɲ ɲɜɢɞɤɨɝɨ, ɭ ɩɨɪɿɜɧɹɧɧɿ ɡ ɩɟɪɟɞɛɚɱɟɧɧɹɦɢ ɬɟɨɪɿʀ, ɡɦɟɧɲɟɧɧɹ ɜɟɥɢɱɢɧɢ ǻV ɩɪɢ ɞɨɫɬɚɬɧɶɨ ɡɧɚɱɧɨɦɭ ɜɿɞɞɚɥɟɧɧɿ ɜɿɞ Ɍɫ ɭ ɛɿɤ ɜɢɫɨɤɢɯ ɬɟɦɩɟɪɚɬɭɪ. Ɇɿɤɪɨɫɤɨɩɿɱɧɢɣ ɪɨɡɪɚɯɭɧɨɤ ɮɥɭɤɬɭɚɰɿɣɧɨʀ ɩɨɩɪɚɜɤɢ ɜ ɩɪɨɜɿɞɧɿɫɬɶ ɡ ɭɪɚɯɭɜɚɧɧɹɦ ɜɫɿɯ ɤɨɦɩɨɧɟɧɬ ɩɚɪɚɦɟɬɪɚ ɩɨɪɹɞɤɭ ɛɭɜ ɩɪɨɜɟɞɟɧɢɣ ɜ ɪɨɛɨɬɚɯ ȼɚɪɥɚɦɨɜɚ ɡ ɫɩɿɜɚɜɬɨɪɚɦɢ [16]. ɉɨɪɿɜɧɹɧɧɹ ɧɚɲɢɯ ɞɚɧɢɯ ɡ ɬɟɨɪɿɽɸ [16] ɩɨɤɚɡɚɥɨ, ɳɨ, ɹɤ ɿ ɭ ɜɢɩɚɞɤɭ ɛɟɡɞɨɦɿɲɤɨɜɢɯ ɩɥɿɜɤɨɜɢɯ ɡɪɚɡɤɿɜ YBaCuO [15], ǻV ɦɨɠɟ ɛɭɬɢ ɨɩɢɫɚɧɚ ɜ ɦɟɠɚɯ ɩɨɥɿɩɲɟɧɨʀ ɬɟɨɪɿʀ Ɏɉ ɞɨ ɬɟɦɩɟɪɚɬɭɪ ɛɥɢɡɶɤɨ 1,35 Ɍɫ. ȼɿɪɨɝɿɞɧɨ, ɫɚɦɟ ɜ ɰɿɣ ɬɟɦɩɟɪɚɬɭɪɧɿɣ ɨɛɥɚɫɬɿ ɜɿɞɛɭɜɚɽɬɶɫɹ ɩɟɪɟɯɿɞ ɞɨ ɩɫɟɜɞɨɳɿɥɢɧɧɨɝɨ ɪɟɠɢɦɭ, ɹɤɢɣ ɞɟɬɚɥɶɧɿɲɟ ɚɧɚɥɿɡɭɽɬɶɫɹ ɧɚɦɢ ɜ [17]. ȼɂɋɇɈȼɄɂ Ɍɚɤɢɦ ɱɢɧɨɦ, ɡ ɜɫɶɨɝɨ ɜɢɳɟɫɤɚɡɚɧɨɝɨ ɦɨɠɧɚ ɡɪɨɛɢɬɢ ɜɢɫɧɨɜɨɤ, ɳɨ ɜɿɞɯɢɥɟɧɧɹ ɜɿɞ ɥɿɧɿɣɧɨɫɬɿ ɡɚɥɟɠɧɨɫɬɟɣ ȡab(Ɍ) ɩɪɢ Ɍɫ < Ɍ < 1,35 Ɍɫ ɜ ɦɨɧɨɤɪɢɫɬɚɥɚɯ YBa2Cu3-zAlzO7-į (z”0,5) ɦɨɠɟ ɛɭɬɢ ɡɚɞɨɜɿɥɶɧɨ ɩɨɹɫɧɟɧɟ ɜ ɦɟɠɚɯ ɬɟɨɪɿʀ ɮɥɭɤɬɭɚɰɿɣɧɨʀ ɧɚɞɩɪɨɜɿɞɧɨɫɬɿ [9,10]. ɉɪɢ ɰɶɨɦɭ ɛɟɡɩɨɫɟɪɟɞɧɶɨ ɩɨɛɥɢɡɭ Ɍɫ Ɏɉ ɞɨɛɪɟ ɨɩɢɫɭɽɬɶɫɹ ɬɪɢɜɢɦɿɪɧɨɸ ɦɨɞɟɥɥɸ Ⱥɫɥɚɦɚɡɨɜɚ-Ʌɚɪɤɿɧɚ. Ⱦɨɤɥɚɞɚɧɧɹ ɦɚɝɧɿɬɧɨɝɨ ɩɨɥɹ ɩɪɢɜɨɞɢɬɶ ɞɨ ɿɫɬɨɬɧɨɝɨ ɡɜɭɠɟɧɧɹ ɬɟɦɩɟɪɚɬɭɪɧɨɝɨ ɿɧɬɟɪɜɚɥɭ ɿɫɧɭɜɚɧɧɹ ɬɪɢɜɢɦɿɪɧɢɯ ɧɚɞɩɪɨɜɿɞɧɢɯ ɮɥɭɤɬɭɚɰɿɣ. ɇɟɦɨɧɨɬɨɧɧɚ ɡɚɥɟɠɧɿɫɬɶ ɜɟɥɢɱɢɧɢ [ɫ(0) ɜɿɞ ɦɚɝɧɿɬɧɨɝɨ ɩɨɥɹ, ɣɦɨɜɿɪɧɨ, ɦɨɠɟ ɛɭɬɢ ɩɨɜ 'ɹɡɚɧɚ ɡ ɩɪɢɝɧɿɱɟɧɧɹɦ ɧɚɞɥɢɲɤɨɜɨʀ ɮɥɭɤɬɭɚɰɿɣɧɨʀ ɩɪɨɜɿɞɧɨɫɬɿ ɜ ɨɛɥɚɫɬɿ ɫɥɚɛɤɢɯ ɦɚɝɧɿɬɧɢɯ ɩɨɥɿɜ .
ɋɉɂɋɈɄ ɅȱɌȿɊȺɌɍɊɂ 1. R.B. Van Dover, L.F. Schneemeyer, J.V. Waszczak, D.A. Rudman, J.Y. Juang, and J.A. Cutro Extraordinary effect of aluminum of aluminum substitution on upper critical field of Ba 2YCu3O 7 // Phys. Rev. B. – 1989. – Vol.39. – P.29322935. 2. Ɇ.Ⱥ. Ɉɛɨɥɟɧɫɶɤɢɣ, Ⱥ.ȼ. Ȼɨɧɞɚɪɟɧɤɨ, ȼ.Ⱥ. ɒɤɥɨɜɫɤɢɣ, Ɇ. ɗɥɶ-ɋɢɢɞɚɜɢ, Ɋ.ȼ. ȼɨɜɤ, Ⱥ.ȼ. ɋɚɦɨɣɥɨɜ, Ⱦ. ɇɢɚɪɯɨɫ, Ɇ. ɉɢɫɫɚɫ, Ƚ. Ʉɚɥɥɢɚɫ, Ⱥ.Ƚ. ɋɢɜɚɤɨɜ ɋɜɟɪɯɩɪɨɜɨɞɹɳɢɟ ɩɚɪɚɦɟɬɪɵ ɢ ɞɢɧɚɦɢɤɚ ɜɢɯɪɟɣ ɜ ɞɨɩɢɪɨɜɚɧɧɵɯ ɚɥɸɦɢɧɢɟɦ ɦɨɧɨɤɪɢɫɬɚɥɥɚɯ YBaCuO // ɎɇɌ. – 1995. – Ɍ.21, ʋ12. –ɋ.1200-1207. 3. R.H. Koch, V. Foglietti, W.J. Gallagher Experimental evidence for vortex glass superconductivity in YBa2Cu3-yAlyO7-x //

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EFFECT OF THE TRANSVERSAL MAGNETIC FIELD ON FLUCTUATION PARACONDUCTIVITY OF YBa2Cu3-zAlzO7-į SINGLE CRYSTALS ALLOYED BY ALUMINIUM WITH THE GIVEN TOPOLOGY OF TWIN BOUNDARIES R.V. Vovk
V.N. Karazin Kharkov National University Svoboda sq. 4, Kharkov, 61077, Ukraine. email: Ruslan.V.Vovk@univer.kharkov.ua In this work, effect of the magnetic field up to 12.7 kE on temperature dependences of conductivity of YBaCuO single crystals alloyed by an aluminium with the system of the unidirectional twin boundaries are investigated. On the basis of the resistivity measured temperature dependences of excess paraconductivity and field dependence off-plane coherent length [ɫ(0,ɇ) were determined. Temperature dependences of excess paraconductivity discussed in terms of the Hikami - Larkin theory of the fluctuation conductivity for layered superconductivity systems. The reasons of suppression of three-dimensional superconductivity fluctuations and field dependence off-plane coherent length [ɫ(0,ɇ) in the weak magnetic fields during the orientation of vector of the magnetic field along c axis are discussed. KEYWORDS: fluctuation conductivity, YBa2Cu3O7-į single crystals, twin boundaries, crossover, alloy, coherence length.