Effects of manganese doping on magnetocaloric effect in Ge-rich Gd 5Ge2.05Si1.95 alloy

Yüzüak E., DİNÇER İ., Elerman Y.

Journal of Rare Earths, cilt.30, sa.3, ss.217-221, 2012 (SCI-Expanded) identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 30 Sayı: 3
  • Basım Tarihi: 2012
  • Doi Numarası: 10.1016/s1002-0721(12)60026-x
  • Dergi Adı: Journal of Rare Earths
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.217-221
  • Anahtar Kelimeler: Entropy change, Magnetic materials, Magnetocaloric effect, Rare earths
  • Ankara Üniversitesi Adresli: Evet

Özet

The structure, magnetic and magnetocaloric properties of the Ge-rich Gd5Ge2.05-xSi1.95-xMn2x (x=0.01 and 0.03) alloys were investigated by scanning electron microscopy, X-ray powder diffraction, differential scanning calorimeter (DSC) and magnetization measurements. The results of energy dispersive X-ray analysis (EDX) and X-ray diffraction analyses showed that the composition and crystal structure of the alloys were desired. DSC measurements were performed to determine the transformation temperatures for each alloy. Both alloys exhibited the first order phase transition around room temperature. The alloys showed an anti-ferromagnetic transition around 60 K. The isothermal magnetic entropy changes of the alloys were determined from the isothermal magnetization measurements by using the Maxwell relation. The maximum values of isothermal magnetic entropy change of the Gd5Ge2.05-xSi 1.95-xMn2x alloy with x=0.01 was found to be -12.1 and -19.8 J/(kg K) using Maxwell equation around 268 K in applied fields of 2 and 5 T, respectively.