硅酸盐学报2018，Vol.46Issue(3)：377-381,5.DOI:10.14062/j.issn.0454-5648.2018.03.10
La0.65Sr0.2Gd0.15MnO3纳米颗粒的制备及其磁热效应
Synthesis and Magnetocaloric in La0.65Sr0.2Gd0.15MnO3 Nanoparticles
摘要
Abstract
Polycrystalline perovskite-type manganite La0.65Sr0.35-xGdxMnO3(x=0-0.2) was prepared by Pechini method. The crystalline phases of the samples were carried out by X-ray powder diffraction with Cu Kα radiation from 20° to 80°. The X-ray diffraction results revealed all the samples exhibits rhombohedra perovskite structure. The morphologies of samples were respected by scanning electron microscope. Magnetic properties and Curie temperature are measured by superconducting quantum interference device. Magnetization as a function of temperature shows that all samples exhibit a paramagnetic-ferromagnetic phase transition at the Curie temperature. The Curie temperature is found to decrease from 350 to 280K upon Gd doping from 0 to 0.2. Forx=0.15, the Curie temperature of the sample was determined to be 300K. The magnetic entropy change deduced from the measured magnetization data using Maxwell relation. The maximum value of isothermal entropy change is found to be 1.87J/(kg·K) under a magnetic field change of 3T and about 215.76J/kg of relative cooling power was obtained near the Curie temperature. The first-order or the second-order on the phase transition of the manganite was distinguished by Banerjee criteria. The high relative cooling power value and the absence of magnetic hysteresis suggest the studied sample can have potential applications for magnetic refrigeration near room temperature.关键词
磁热效应/Curie温度/钙钛矿Key words
magnetocaloric effect/Curie temperature/perovskite分类
信息技术与安全科学引用本文复制引用
孔祥宇,邹正光..La0.65Sr0.2Gd0.15MnO3纳米颗粒的制备及其磁热效应[J].硅酸盐学报,2018,46(3):377-381,5.基金项目
国家自然科学基金(51562006)资助. （51562006）
