Tuning the magnetic phase transition and the magnetocaloric properties of La0.7Ca0.3MnO3 compounds through Sm-doping

Tran Dang Thanh,Dong-Hyun Kim,Seong-Cho Yu,Nguyen Van Dang,The Long Phan,Le Viet Bau,Kieu Xuan Hau,Nguyen Thi Dung,Hong-Guang Piao,Pham Duc Huyen Yen

doi:10.1063/1.5007285

Abstract

In this work, we point out that the width and the nature of the magnetic phase transition, TC value, and as well as magnetocaloric effect in La0.7-xSmxCa0.3MnO3 compounds can be easily modified through Sm-doped into La-site. With an increasing Sm concentration, a systematic decrease in the magnetization, TC, and magnetic entropy change (ΔSm) are observed. The Arrott-plot proveds that the samples with x = 0 and 0.1 undergoing a first-order phase transition. Meanwhile, sample x = 0.2 undergoes a second-order phase transition, which exhibits a high value of the relative cooling power (81.5 J/kg at ΔH = 10 kOe). An analysis of the critical behavior based on the modified Arrott plots method has been done for sample x = 0.2. The results proved a coexistence of the long- and short-range interactions in La0.5Sm0.2Ca0.3MnO3 compound.

Highlights

It has been found that La0.7Ca0.3MnO3 (LCMO) as a typical material exhibiting the colossal magnetoresistance (MR) and giant magnetocaloric (MC) effects
It is known that the ferromagnetic-paramagnetic (FM-PM) transition in LCMO polycrystalline or single crystal bulk sample is discontinuous and followed up with structure changes, which is known as a first-order phase transition (FOPT).[1,2,3]
According to the some previous reports, the FOPT in LCMO bulk sample can be rounded to the second-order phase transition (SOPT) based on quenched discontinuousness upon the doping suitable elements into the La/Ca5–7 and/or Mn sites,[8] reduced dimensionality,[9] reduced crystalline or particle size.[2,10]

Summary

INTRODUCTION

It has been found that La0.7Ca0.3MnO3 (LCMO) as a typical material exhibiting the colossal magnetoresistance (MR) and giant magnetocaloric (MC) effects. According to the some previous reports, the FOPT in LCMO bulk sample can be rounded to the SOPT based on quenched discontinuousness upon the doping suitable elements into the La/Ca5–7 and/or Mn sites,[8] reduced dimensionality,[9] reduced crystalline or particle size.[2,10]. According to Anwar et al,[5] the FM-PM transition undergoes a FOPT in parent sample and a SOPT in Sm-doped samples of La0.7-xSmxCa0.3MnO3 (LSCMO).

EXPERIMENT

RESULTS AND DISCUSSION

CONCLUSION