【摘 要】
：
A comparative study for two different series,La0.67Ca0.33Mn1-xCrxO3 and La0.67+xCa0.33-xMn1-x CrxO3,is performed with x changing from 0.04 to 0.08 through measu
【机 构】
：
School of Physics Science and Technology,Department of Physics.Huazhong University of Science and Te
【出 处】
：
武汉理工大学学报（材料科学版）（英文版）
论文部分内容阅读
A comparative study for two different series,La0.67Ca0.33Mn1-xCrxO3 and La0.67+xCa0.33-xMn1-x CrxO3,is performed with x changing from 0.04 to 0.08 through measurements of zero-field resistivity (ρ) magnetoresistance(MR) and ac susceptibility (x) as functions of temperature(T). For the second group,a single insulator-metal transition was characterized by the resistivity maximum appears in ρ VS.T curve.For the first group,besides the resistivity peak appearing at higher temperatures,the sample shows evidence for the existence of another peak appearing at lower temperatures.Compared to the first group,the second group shows a significant enhancement in MR effect,while the measurement of x-T dependence does not display obvious differences for the two series.Different behaviors observed in the tWO series are discussed by considering possible exchange interaction between Mn3+ ion and Cr3+ ion.
其他文献
随着人类科技发展的不断进步，在生活和工作中人们对环境的要求也在逐渐的提高，从而促进在工程建筑中建筑与电气系统的广泛结合。建筑物中的电气化设备也越来越复杂化。因电器短
介绍了RFID技术的特点,探讨了RFID技术在生产加工、储存、运输、销售等几个环节的应用和影响.
2012年1月9日,河南莲花味精股份有限公司在郑州皇冠假日宾馆举行2012新品发布会。此次发布会以＂味精新标准,健康新生活＂为主题,诚邀来自全国各地的代理商、加盟商以及新闻界的
The gene iscS-2 from extremophile Acidithiobacillus ferrooxidans may play a crucial role in nitrogenase maturation. To investigate the protein encoded by this g
随着我国经济的飞速发展,为防治污染、防治生态破坏,环境保护意识逐渐增加.林业作为一项产业及社会公益事业,林业在生态环境保护中具有重大作用,是实现可持续发展的保证.
A theoretical model based on BCT lattice structure was developed.Resultant force in the BCT lattice structure was deduced,following the interaction force of two
The performance of a rotating packed bed(RPBl with three kinds of packings was investigated using alcohol/water solution under continuous distillation condition
Selective reduction of laterite ores followed by acid leaching is a promising method to recover nickel and cobalt metal, leaving leaching residue as a suitable
黄瓜立枯病是由立枯丝核菌侵染引起的真菌性病害，该病是黄瓜苗期的主要病害之一。近年来，该病在信阳市保护地黄瓜上发生危害日益严重。本文阐述了黄瓜立枯病的症状、发生和危害
要做好医院传染病的管理工作,需要以相关法律法规的规定为依据,对涉及传染病管理的各个方面认真加以规范,做到管理制度完善、组织机构健全、人员培训到位、监督反馈及时,确保