中文摘要：

对具有电脉冲诱发电阻可逆变化（EPIR）特性的多晶La0.9Ca0.1MnO3在相同条件下经氩气和氧气退火后样品的磁矩和比热进行了研究.实验结果表明,经氧气退火后的磁矩和比热分别比氩气退火后的磁矩和比热增大.对氧气退火后的比热和氩气退火后的比热做差处理后发现,两种气氛退火后的比热差与T3/2成线性关系.经氧气和氩气退火后的区别在于氧离子浓度的变化.经氧气退火后,氧离子浓度增加,导致样品中铁磁区域的增大,引起磁矩和比热增大.退火后磁矩和比热的变化与EPIR效应中磁矩和比热随电阻状态的变化趋势一致,表明EPIR效应与氧含量的变化有关.

英文摘要：

Magnetic moment and specific heat of La0.9Ca0.1MnO3 after heat treatment in oxygen and argon were studied. It is found that the sample after oxygen treatment has higher magnetic moment and specific heat than that after argon treatment. The difference of specific heat between the samples after oxygen treatment and after argon treatment has linear relationship with T3/2. The heat treatment in oxygen and argon would induce the change of oxygen density which effect the magnetic moment and specific heat. For EPIR effect, the increase of ferromagnetic regions induced by oxygen motion driven by electric pulses would in- crease the magnetic moment and specific heat, and the different of specific heat between low resistance state and high resistance state has linear relationship with T3/2. According to oxygen motion driven by electric pulses model, the low resistance state has higher oxygen density than high resistance state. It implies that the increase of magnetic moment and specific heat with resistance decreasing may arise from the oxygen motion driven by electric pulses for EPIR effect.