Magnetic and magnetotransport behavior of RFe5Al7 (R = Gd and Dy): Observation of reentrant inverse-magnetocaloric phenomenon and asymmetric magnetoresistance behavior

被引：11

作者：

Chandragiri, Venkatesh ^{[1
]}

Iyer, Kartik K. ^{[1
]}

Sampathkumaran, E. V. ^{[1
]}

机构：

[1] Tata Inst Fundamental Res, Mumbai 400005, Maharashtra, India

来源：

PHYSICAL REVIEW B | 2015年 / 92卷 / 01期

关键词：

FERRIMAGNETISM;

D O I：

10.1103/PhysRevB.92.014407

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

We have compared and contrasted magnetic, magnetocaloric, and magnetoresistive properties of Gd and Dy members of the rare-earth (R) series RFe5Al7, crystallizing in ThMn12 structure, known to order antiferromagnetically. Among other observations, we would like to emphasize the following findings: (i) There are multiple sign crossovers in the temperature (T) dependence of isothermal entropy change (Delta S) in the case of Dy compound. In addition to nil Delta S at themagnetic compensation point known for two-magnetic-sublattice systems, there is an additional sign crossover at low temperatures, as though there is a "reentrant inverse-magnetocaloric" phenomenon. Corresponding sign reversals could also be observed in the magnetoresistance data. (ii) The plots of magnetoresistance versus magnetic field are found to be highly asymmetric with the reversal of the direction of magnetic field (H) well below T-N for both compounds, similar to those known for antiferromagnetic tunnel junctions. We attribute these to subtle changes in spin orientations of R and Fe moments induced by T and H.

引用

页数：7