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对电脉冲诱导的不同电阻态下La0.7Ca0.3MnO3样品的比热进行了研究.实验结果表明,电脉冲导致La0.7Ca0.3MnO3样品比热随电阻状态发生可逆变化.比热随电阻状态的减小而减小.低温比热拟合及不同电阻状态下的比热差与温度关系说明,声子对比热的贡献不随电阻状态变化,磁性和载流子对比热的贡献是导致La0.7Ca0.3MnO3样品比热变化的原因.电脉冲诱导O离子沿一维扩展性缺陷的电化学迁移,导致材料中局部区域的O离子浓度发生变化.O离子浓度的变化导致载流子浓度的变化,同时载流子浓度的变化将使得低温下磁性耦合强度发生变化,从而导致比热发生变化.
The specific heat of La0.7Ca0.3MnO3 samples with different resistance states induced by electrical impulses was investigated.The experimental results show that the specific heat of La0.7Ca0.3MnO3 sample reversibly changes with the electrical resistance due to the electrical pulse.The specific heat varies with the state of resistance Decrease and decrease.The relationship between specific heat and temperature at different specific temperature and different specific resistance states shows that the contribution of phonons to the specific heat does not change with the state of resistance and the contribution of magnetic and carrier heat of contrast is caused by La0.7Ca0 .3MnO3 samples cause specific heat changes.Electrical impulses induce the electrochemical migration of O ions along the one-dimensional scarcity defects resulting in changes in the concentration of O ions in the localized regions of the material.Changes in the concentration of O ions result in changes in carrier concentration, At the same time, the change of carrier concentration will change the magnetic coupling strength at low temperature, resulting in the change of specific heat.