Importance of site occupancy and absence of strain glassy phase in Ni2−xFexMn1.5In0.5

• Published in: Journal of alloys and compounds 2019-08, Vol.797, p.995-1001
• Main Authors: Nevgi, R., Das, Gangadhar, Acet, M., Priolkar, K.R.
• Format: Article
• Language: English
• Subjects: Ferromagnet; Ferromagnetic phases; Ferromagnetism; Ground state; Magnetic properties; Manganese; Ni2−xFexMn1.5In0.5; Nickel; Occupancy; Strain glass; Transition temperature
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2019.05.172

Martensitic transition temperature steadily decreases in Ni2−xFexMn1.5In0.5 and is completely suppressed at x = 0.2. Despite suppression of martensitic transition, Ni1.8Fe0.2Mn1.5In0.5 does not display the expected strain glassy phase. Instead, a ground state with dominant ferromagnetic interactions is observed. A study of structural and magnetic properties of x = 0.2 reveal that the alloy consists of a major Fe rich cubic phase and a minor Fe deficient monoclinic phase favoring a ferromagnetic ground state. This is exactly opposite of that observed in Ni2Mn1−yFeyIn0.5 wherein a strain glassy phase is observed for y = 0.1. The change in site symmetry of Fe when doped for Ni in contrast to Mn in the Heusler composition seems to support the growth of the ferromagnetic phase. •Ni1.8Fe0.2Mn1.5In0.5 despite impurity doping does not display strain glassy phase.•Ni1.8Fe0.2Mn1.5In0.5 phase separates into major cubic ferromagnetic phase and minor martensitic phase.•Ground state of Ni1.8Fe0.2Mn1.5In0.5 is exact opposite of strain glassy Ni2Mn1.4Fe0.1In0.5.•Site symmetry of the dopant atoms plays a role in driving structural and magnetic interactions.