【摘要】 采用溶胶 凝胶(sol gel)法制备了名义组分为La0.67Sr0.33-xAgxMnO3(x=0.15、0.20)的多晶样品,发现用Ag部分替代Sr后样品的室温磁电阻比替代前明显增大。在1.8T下,La0.67Sr0.18Ag0.15MnO3样品的磁电阻在330K出现峰值,其峰值为35%;对于La0.67Sr0.13Ag0.2MnO3样品,磁电阻峰值为26%,且峰的宽度较大,在290～315K之间的磁电阻随着温度变化不大,因此显著提高了室温时样品的磁电阻和磁电阻的温度稳定性,另外,还提高了样品的磁场灵敏度,这对磁电阻的应用有很大意义。更多还原

【Abstract】 La_0.67Sr_0.33-xAg_xMnO₃ polycrystalline sample were synthesized by sol-gel method. It is found that the room temperature magnetoresistance of this kind material was obviously larger than La_0.67Sr_0.33MnO₃. Under an applied filed of 1.8T, there was a MR maximum 35% of La_0.67Sr_0.18Ag_0.15MnO₃ at 330K; and a MR maximum 26% of La_0.67Sr_0.13Ag_0.20MnO₃ at 300K. Comparing with La_0.67Sr_0.33MnO₃, not only the MR value of the sample La_0.67Sr_0.13Ag_0.2MnO₃ was increased but also temperature stability of magentoresistance was improved at room temperature range, moreover field susceptivity was also highly improved, which was important for the application of this magnetoresistance material.更多还原