Chen Lili, Fan Jiyu, Tong Wei, Hu Dazhi, Ji Yanda, Liu Jindong, Zhang Lei, Pi Li, Zhang Yuheng, Yang Hao
Department of Applied Physics, Nanjing University of Aeronautics and Astronautics, Nanjing, 210016, China.
High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei, 230031, China.
Sci Rep. 2016 Dec 5;6(1):14. doi: 10.1038/s41598-016-0009-0.
Magnetic and electronic transport properties of perovskite manganite LaErSrMnO have been thoroughly examined through the measurements of magnetization, electron paramagnetic resonance(EPR), and resistivity. It was found that the substitution of Er for La ions introduced the chemical disorder and additional strain in this sample. An extra resonance signal occurred in EPR spectra at high temperatures well above T gives a strong evidence of electronic phase separation(EPS). The analysis of resistivity enable us to identify the polaronic transport mechanism in the paramagnetic region. At low temperature, a new ferromagnetic interaction generates in the microdomains of Er-disorder causing the second increase of magnetization. However, the new ferromagnetic interaction does not improve but decreases electronic transport due to the enhancement of interface resistance among neighboring domains. In view of a really wide temperature region for the EPS existence, this sample provides an ideal platform to uncover the evolution law of different magnetic structures in perovskite manganites.
通过对磁化强度、电子顺磁共振（EPR）和电阻率的测量，对钙钛矿锰氧化物LaErSrMnO的磁性和电子输运性质进行了全面研究。研究发现，用Er取代La离子会在该样品中引入化学无序和额外应变。在远高于居里温度（(T)）的高温下，EPR谱中出现了一个额外的共振信号，这有力地证明了电子相分离（EPS）的存在。对电阻率的分析使我们能够确定顺磁区域中的极化子输运机制。在低温下，在Er无序的微区中产生了一种新的铁磁相互作用，导致磁化强度再次增加。然而，由于相邻区域间界面电阻的增大，这种新的铁磁相互作用并没有改善反而降低了电子输运。鉴于EPS存在的温度范围非常宽，该样品为揭示钙钛矿锰氧化物中不同磁性结构的演化规律提供了一个理想的平台。
