Nd_(1.67)Sr_(0.33)NiO_4中的热导反常  

Anomalous thermal conductivity in Nd_(1.67)Sr_(0.33)NiO_4

作　　者：高惠平[1] 李波[1] 余勇[1] 阮可青[1] 吴柏枚[1] 

机构地区：[1]中国科学技术大学结构分析开放实验室,物理系合肥230026

出　　处：《物理学报》2004年第11期3853-3857,共5页Acta Physica Sinica

基　　金：国家自然科学基金 (批准号 :10 1740 70和 10 10 40 13 );国家重点基础研究专项基金 (批准号 :G19990 64 6)资助的课题~~

摘　　要：报道了两个典型掺杂的镍氧化物Nd2 -xSrxNiO4 (x=0 33,1 35 )的低温热导率、电阻率和低场交流磁化率 ,测试温区为 77— 30 0K .在Nd2 -xSrxNiO4 (x=0 33)样品的热导率_温度曲线上在电荷有序转变温度 (TCO)和自旋有序转变温度 (TSO)附近分别观测到反常 ,电荷有序使热导率在TCO 以下有所增加 ,反铁磁自旋有序使热导率在TSO 附近被压制 .在低场交流磁化率_温度曲线上也分别观测到对电荷有序和自旋有序的响应 ,而在其电阻率_温度曲线上仅观测到电荷有序 .作为比较 ,Nd0 6 5Sr1 35NiO4 样品中没有观测到输运性质和磁性质上的反常 .两个样品中声子热导占主导地位 .Nd1 6 7Sr0 33NiO4The temperature dependence of thermal conductivity (K), resistivity (ρ) and low field ac susceptibility (χ) of perovskite nickelates Nd 2-xSr xNiO 4 (x=0.33, 1.35) have been measured at temperatures from 77 to 300 K. The thermal conductivity anomalies associated with charge_order (CO) and spin_order (SO) are observed simultaneously in Nd 1.67Sr 0.33NiO 4 for the first time so far as we know. The thermal conductivity is enhanced below T CO, but is suppressed near T SO. There is also response to CO and SO in the χ-Τ curve. Only CO is observed in the ρ-Τ curve. In contrast, there are no anomalies in K-Τ, ρ-Τ and χ-Τ of Nd 0.65Sr 1.35NiO 4. The anomalous phonon thermal conductivity in Nd 1.67Sr 0.33NiO 4 indicates that there are strong charge_phonon interaction and the spin_phonon interaction in this compound.

关 键 词：自旋 电荷 反铁磁 交流磁化率 磁性质 声子 有序 Nd1 低场 反常 

分 类 号：O551.3[理学—热学与物质分子运动论]