【摘要】 本文研究了Pr1.27La0.7Ce0.03CuO4和Pr2CuO4单晶的低温热导率行为,在极低温下热导率(κ)随磁场的变化显示出低场下的"凹陷"和高场下的"平台"现象.这种现象很可能是顺磁离子散射声子的作用引起的,在Pr2CuO4单晶的比热测量结果中,肖特基峰随磁场的变化关系表明样品中确实含有少量的顺磁离子,并且其零场下基态能级存在劈裂.因此,这些顺磁离子很可能是Pr4+离子.该结果表明铜氧化合物高温超导体中声子与自旋的强烈耦合作用.更多还原

【Abstract】 In this paper,we study the magnetic-filed (H) dependence of the low-temperature thermal conductivity (κ) of Pr1.27La0.7Ce0.03CuO4 and Pr2CuO4 crystals,which shows a "diplike" feature at low filed and a "plateau" feature at high filed. These phenomena are discussed to be due to the scattering of phonons by paramagnetic ions. The specific heat data of Pr2CuO4 crystals indicate that the paramagnetic ions are likely Pr4+ ions with zero-field splitting ground state. The present result demonstrates a strong spin-phonon coupling in high-Tc cuprates.更多还原