Spin-Gap Formation and Thermal Structural Studies in Reduced Hybrid Layered Vanadates
作者:Bangbo Yan、Junhua Luo、Paul Dube、Athena S. Sefat、John E. Greedan、Paul A. Maggard
DOI:10.1021/ic0604563
日期:2006.6.1
Reduced layered M(C4H4N2)V4O10 ((I, M = Co; II, M = Ni; III, M = Zn); C4H4N2 = pyrazine, pyz) hybrid solids were synthesized via hydrothermal reactions at 200-230 degrees C, and their structures determined by single-crystal X-ray diffraction (Cmcm, No. 63, Z = 4; a = 14.311(2), 14.2372(4), 14.425(1) A; b = 6.997(1), 6.9008(2), 6.9702(6) A; and c = 11.4990(8), 11.5102(3), 11.479(1) A; for I, II, and
还原层状M(C4H4N2)V4O10((I,M = Co; II,M = Ni; III,M = Zn); C4H4N2 =吡嗪,pyz)杂化固体是通过200-230摄氏度的水热反应合成的,通过单晶X射线衍射确定的结构(Cmcm,No.63,Z = 4; a = 14.311(2),14.2372(4),14.425(1)A; b = 6.997(1),6.9008(2) ,6.9702(6)A;和c = 11.4990(8),11.5102(3),11.479(1)A;分别用于I,II和III)。所有这三种固体都是同构的,并且包含由边和角共享的VO5方锥缩合而成的V4O102-层。单个对称唯一的V原子平均还原1/2个电子,并通过其顶部的氧原子键合到层间Mpyz2 +链上。磁化率测量结果显示出很强的温度依赖性和居里常数,这与每个III的V4O10(2-)公式的两个随机局部自旋一致。此外,对