高压合成双钙钛矿Y_(2)NiIrO_(6)中场冷诱导的巨磁电阻效应  

Cooling Fields Induced Giant Magnetoresistance in High-Pressure Synthesized Double Perovskite Y_(2)NiIrO_(6)

作　　者：彭毅 邓正[1,2] 李文敏 史鲁川[1,2] 赵建发 张俊 望贤成 靳常青[1,2] PENG Yi;DENG Zheng;LI Wenmin;SHI Luchuan;ZHAO Jianfa;ZHANG Jun;WANG Xiancheng;JIN Changqing(Institute of Physics,Chinese Academy of Sciences,Beijing 100190,China;School of Physics,University of Chinese Academy of Sciences,Beijing 101408,China;Institute of Quantum Materials and Physics,Henan Academy of Sciences,Zhengzhou 450046,Henan,China)

机构地区：[1]中国科学院物理研究所,北京100190 [2]中国科学院大学物理学院,北京101408 [3]河南省科学院量子材料与物理研究所,河南郑州450046

出　　处：《高压物理学报》2024年第1期37-43,共7页Chinese Journal of High Pressure Physics

基　　金：北京市自然科学基金(2212049);国家自然科学基金(11974407)。

摘　　要：双钙钛矿材料Y_(2)NiIrO_(6)的亚铁磁转变温度为192 K,因其奇异的交换偏置效应而受到广泛关注。系统研究了Y_(2)NiIrO_(6)的低温晶体结构、电导行为及磁电阻性能,发现该材料在130 K时保持了290 K时的晶体结构,并在130~300 K的温区内表现出半导体电导行为。在居里温度以上的顺磁状态,其导电行为可以用Efros-Shklovskii变程跃迁模型拟合,在居里温度以下,亚铁磁有序使电阻行为偏离该模型。更为有趣的是,亚铁磁序诱导了材料的负磁电阻效应,并且7.0 T的场冷诱导了–10%的巨磁电阻效应。这一新机制为探索新型巨磁电阻材料提供了全新的研究思路。Double perovskite Y_(2)NiIrO_(6) is a ferrimagnetic material with Curie temperature of 192 K.It has drawn wide attention owing to its remarkable exchange-bias effect.Here,we studied the low-temperature crystal structure,electron transport properties and magnetoresistance of Y_(2)NiIrO_(6).The crystal structure under 130 K is almost identical with that of room-temperature.The material shows semiconducting behavior in the temperature range of 130 to 300 K.Above Curie temperature it can be well describe as Efros-Shklovskii variable-range hopping model.Below Curie temperature,a departure occurs due to the forming of long-range ferrimagnetic ordering.It is interesting to find that the magnetic ordering results into negative magnetoresistance.Moreover,giant magnetoresistance up to–10%is induced by cooling field of 7.0 T.This mechanism of this remarkable effect provides a new boulevard to discover new type of giant magnetoresistance materials.

关 键 词：高压合成 双钙钛矿 交换偏置 巨磁电阻效应 

分 类 号：O521.2[理学—高压高温物理]