Nd1.67Sr0.33NiO4中的热导反常

报道了两个典型掺杂的镍氧化物Nd＿2-xSr＿xNiO＿4(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—300K. 在Nd＿2-xSr＿xNiO＿4 (x=0.33)样品的热导率-温度曲线上在电荷有序转 变温度（T＿CO）和自旋有序转变温度（T＿SO）附近分别观测到反常， 电荷有序使热导率在T＿CO以下有所增加，反铁磁自旋有序使热导率在T＿SO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，Nd＿1.67Sr0.33NiO＿4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. Nd＿1.67Sr0.33NiO＿4样品中电荷有序和自旋有序导致的热导 率的反常表明样品中存在强的电荷-声子和自旋-声子相互作用. 关键词：热导率电荷有序自旋有序

Anomalous thermal conductivity in Nd1.67Sr0.33NiO4

The temperature dependence of thermal conductivity (K),resistivity (ρ) and low field ac susceptibility (χ) of perovskite nick elates Nd＿2-xSr＿xNiO＿4(x =0.33,1.35) have been measured at temperatures from 77 to 300 K. The thermal conductivity an omalies associated with charge_order (CO) and spin_order (SO) are observed simultaneously in Nd＿1.67Sr0.33NiO＿4 for the firs t 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 S O in the χ-Τ curve. Only CO is observed in the ρ-Τ curve. In contrast, th ere are no anomalies in K-Τ, ρ-Τ andχ-Τ of Nd＿1.67Sr0.33NiO＿4. The anomalous phonon thermal conductivi ty in Nd＿1.67Sr0.33NiO＿4 indicates that there are strong charg e_phonon interaction and the spin_phonon interaction in this compound.