热处理中Pr_(0.5)Sr_(0.5)MnO_3薄膜的电学性能变化和应力弛豫  

INFLUENCE OF POST-ANNEALING ON ELECTRIC PROPERTIES OF Pr_(0.5)Sr_(0.5)MnO_3 THIN FILMS

作　　者：李淼[1] 陈莉萍[1] 

机构地区：[1]浙江师范大学物理系,浙江金华321004

出　　处：《低温物理学报》2015年第2期139-143,共5页Low Temperature Physical Letters

基　　金：国家自然科学基金(批准号:11304285);浙江省重点科技创新团队项目(批准号:2011R50012)资助的课题~~

摘　　要：我们用脉冲激光法在(001)LaAlO3衬底上制备了Pr0.5Sr0.5MnO3薄膜,在900℃的空气中进行后退火处理,研究了退火前后薄膜的电磁性能和晶格结构变化.随着温度降低原位生长薄膜在低温段电阻率迅速上升,表现为绝缘体性质.磁化强度-温度曲线表明薄膜具有顺磁-铁磁-反铁磁的相变,并且存在相分离现象.相比之下,退火后薄膜随着温度降低只出现了顺磁绝缘体-铁磁金属相变,在低温区域一直表现为铁磁金属性.x光衍射实验发现退火使得薄膜在垂直于衬底表面方向的晶格伸长量明显减小,表明退火过程中发生了应力弛豫.为了搞清楚后退火中氧含量和应力弛豫的不同作用,我们进行了(110)SrTiO3衬底上Pr0.5Sr0.5MnO3薄膜的后退火对比实验,结果表明退火中的应力弛豫是导致退火前后薄膜电磁性质差异的主要原因.Pr0.5Sr0.5MnO3 thin films on substrates of（001）-oriented LaAlO3 were epitaxially grown by pulsed laser deposition method,and annealed in air at temperature of 900 ℃.We studied the influence of the post-annealing on the electric properties and structure of the films.The as-grown films show paramagnetism-ferromagnetism transition upon cooling,and finally get into antiferromagnetic-insulating state in low temperature.However,the annealed films is ferromagnetic and metallic in ground state.These changes of electric properties are demonstrated to be caused by the strain relaxation during the post-annealing process.

关 键 词：退火处理 锰氧化物薄膜 应力 电学性能 

分 类 号：O484.42[理学—固体物理]