Title :
Complex Magnetic Behavior of the Heusler Alloy—Cu2Mn0.75Fe0.25Al
Author :
Venkateswarlu, Buchepalli ; Babu, P.D. ; Kumar, N. Hari
Author_Institution :
Dept. of Phys., IIT Madras, Chennai, India
Abstract :
We investigated the structural and magnetic properties of Cu2Mn1-xFexAl (x = 0.25, 0.5, 0.75) alloys. Among the three compositions, only x = 0.25 composition crystallizes in single phase with L21 structure but its magnetic response indicates a complex magnetic structure. The magnetic isotherms were fitted to modified Langevin equation which indicates the presence of clusters with large magnetic moment. The ac susceptibility studies showed the presence of a superparamagnetic phase in the system over and above ferromagnetic order. To determine the nature of the interactions among the clusters, the variation of freezing temperature (Tf) with applied ac frequency was analyzed using different models (Néel-Arrhenius, Vogel-Fulcher, and critical slowing down model).
Keywords :
aluminium alloys; copper alloys; crystal structure; crystallisation; ferromagnetic materials; iron alloys; magnetic moments; magnetic structure; magnetic susceptibility; manganese alloys; superparamagnetism; Cu2Mn0.75Fe0.25Al; Heusler alloy; L21 structure; Neel-Arrhenius model; Vogel-Fulcher model; ac susceptibility; complex magnetic structure; critical slowing down model; crystallization; ferromagnetic order; freezing temperature; magnetic isotherm; magnetic moment; magnetic properties; modified Langevin equation; structural properties; superparamagnetic phase; Magnetic hysteresis; Magnetic susceptibility; Magnetization; Metals; Saturation magnetization; Temperature; Temperature measurement; Full Heusler alloys; half-metallicity; spinglass; superparamagnetism;
Journal_Title :
Magnetics, IEEE Transactions on
DOI :
10.1109/TMAG.2014.2323697
