Magnetocaloric Effect Near Room Temperature in Composites Based on Lal.xCax.yAyMnO3 Manganites （A=K, Na）  

作　　者：W. Cheikhrouhou-Koubaa A. Cheikhrouhou 

机构地区：[1]Laboratoire de Physique des Materiaux, Faculte des Sciences de Sfax, Universite de Sfax, Sfax, Tunisie [2]Centre de Recherches en Informatique, Multimedia et Traitement Numdrique des donn~es Technopole de Sfax, Sakietez-zit, Tunisie

出　　处：《Journal of Physical Science and Application》2016年第1期2-2,共1页物理科学与应用（英文版）

摘　　要：We have investigated the magnetic and magnetocaloric properties of Lal.xCax.yAyrvlnO3 （A=K, Na and 0 -〈 x 〈 0.5） polycrystalline samples elaborated using several techniques （solid sate reaction at high temperatures, sol-gel method, SPS route ）. All our samples exhibit a paramagnetic-ferromagnetic transition with decreasing temperature. The Curie temperature Tc depends on the nature and the amount of the substituted element （x, y, Na, K）. From the magnetization measurements versus magnetic applied field M（H）, we have deduced the evolution of the magnetic entropy change ASM （T） and the relative cooling power RCP. Our studies show that our samples exhibit great magnetocaloric effect values near room temperature and consequently may be used in the magnetic refrigeration area. In order to enhance the magnetocaloric effect （MCE）, we have elaborated several composites based on the studied manganites and ferromagnetic oxides and studied its magnetocaloric properties. Our studies show that some composites with appropriate concentrations exhibit good RCP values near room temperature reaching that obtained in gadolinium Gd known as the prototype material for magnetic refrigeration around room temperature.

关 键 词：复合材料 锰氧化物 磁热效应 NA 多晶样品 溶胶-凝胶法 铁磁转变 高温度 

分 类 号：TB33[一般工业技术—材料科学与工程] O614.711[理学—无机化学]