Magnetocaloric properties of (La1-xPrx)(0.85)K0.15MnO3 (x=0.0, 0.1, 0.3 and 0.5) perovskite manganites


AKÇA G. , Cetin S. , Gunes M., EKİCİBİL A.

CERAMICS INTERNATIONAL, vol.42, no.16, pp.19097-19104, 2016 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 42 Issue: 16
  • Publication Date: 2016
  • Doi Number: 10.1016/j.ceramint.2016.09.070
  • Title of Journal : CERAMICS INTERNATIONAL
  • Page Numbers: pp.19097-19104
  • Keywords: Magnetocaloric effect, Magnetic entropy changes, Manganites, Curie temperature, MAGNETIC ENTROPY CHANGE, TEMPERATURE, DY

Abstract

In this study, we have investigated the effect of Pr on the structural, magnetic and magnetocaloric properties of La1-xPrx)(0.85)K0.15MnO3 (x=0.0, 0.1, 0.3 and 0.5) samples synthesized by sol-gel technique. The XRD patterns of samples for x=0.0 and 0.1 are indexed to rhombohedral structure with hexagonal setting (space group R (3) over barc) while the samples for x=0.3 and 0.5 crystallized in the orthorhombic structure with space group Pbnm. Magnetization measurements versus temperature in a magnetic field of 250 Oe indicate that all samples show a ferromagnetic to paramagnetic transition with increasing temperature. The Curie temperature, T-C, decreases with increasing Pr3+ concentration from 238 K for x=0.0-158 IC for x=0.5. We determined the magnetic entropy changes of the samples from M(H) isotherms that were measured around T-C. The values of maximum magnetic entropy change were found to be 4.63, 5.22, 2.80 and 2.30 J kg(-1) K-1 for x=0.0, 0.1, 0.3 and 0.5 for a field change of 2 T, respectively. For LPKM1 sample, we have also calculated the value of adiabatic temperature change as 3.11 K from the heat capacity and isothermal magnetization measurements under magnetic field of 2 T.