Giant magnetocaloric effect in the Gd5Ge2.025Si1.925In0.05 compound


Yuzuak E. , Dincer I., Elerman Y.

CHINESE PHYSICS B, cilt.19, sa.3, 2010 (SCI İndekslerine Giren Dergi) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 19 Konu: 3
  • Basım Tarihi: 2010
  • Doi Numarası: 10.1088/1674-1056/19/3/037502
  • Dergi Adı: CHINESE PHYSICS B

Özet

The magnetocaloric properties of the Gd5Ge2.025Si1.925In0.05 compound have been studied by x-ray diffraction, magnetic and heat capacity measurements. Powder x-ray diffraction measurement shows that the compound has a dominant phase of monoclinic Gd5Ge2Si2-type structure and a small quantity of Gd-5(Ge,Si)(3)-type phase at room temperature. At about 270 K, this compound shows a first order phase transition. The isothermal magnetic entropy change (Delta S-M) is calculated from the temperature and magnetic field dependences of the magnetization and the temperature dependence of MCE in terms of adiabatic temperature change (Delta T-ad) is calculated from the isothermal magnetic entropy change and the temperature variation in zero-field heat-capacity data. The maximum Delta(SM) is -13.6 J.kg(-1).K-1 and maximum Delta T-ad is 13 K for the magnetic field change of 0-5 T. The Debye temperature (theta(D)) of this compound is 149 K and the value of DOS at the Fermi level is 1.6 states/eV.atom from the low temperature zero-field heat-capacity data. A considerable isothermal magnetic entropy change and adiabatic temperature change under a field change of 0-5 T jointly make the Gd5Ge2.025Si1.925In0.05 compound an attractive candidate for a magnetic refrigerant.