Electron Concentration Dependence of Phase Transition and Magnetic Properties in NiMnGa Alloys

KÖK M., AYDOĞDU Y.

JOURNAL OF SUPERCONDUCTIVITY AND NOVEL MAGNETISM, cilt.26, sa.5, ss.1691-1696, 2013 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 26 Sayı: 5
  • Basım Tarihi: 2013
  • Doi Numarası: 10.1007/s10948-012-1849-x
  • Dergi Adı: JOURNAL OF SUPERCONDUCTIVITY AND NOVEL MAGNETISM
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.1691-1696
  • Anahtar Kelimeler: Electron concentration, NiMnGa, Phase transition, Magnetic property, MARTENSITIC TRANSITION, MEMORY
  • Gazi Üniversitesi Adresli: Evet

Özet

The phase transition, Curie temperature and magnetic properties of NiMnGa alloys represented by S1, S2, S3, and S4 in different atomic percentage were investigated from TG/DTA and PPMS measurements. It was found that the electron concentration (e/a) ratio of S1 and S4 as well as S2 and S3 are equal to each other. The transformation temperatures and magnetization values are similar for these alloys having the same e/a. Results show that room temperature magnetization depends on valence electron concentration of alloys and saturation of alloys increases with the decrease of e/a ratio. The measured coercivity values for all alloys were above 125 Oe and they had a long saturation field, i.e., above 10000 Oe, by exhibiting, the characteristics of hard magnetic materials.