Anomalous critical point behavior in dilute magnetic semiconductor (Ca,Na)(Zn,Mn)2Sb2

Abstract

In this paper we report successful synthesis and magnetic properties of (Ca,Na)(Zn,Mn)2Sb2 as a new ferromagnetic dilute magnetic semiconductor (DMS). In this DMS material the concentration of magnetic moments can be controlled independently from the concentration of electric charge carriers that are required for mediating magnetic interactions between these moments. This feature allows us to separately investigate the effect of carriers and of spins on the ferromagnetic properties of this new DMS alloy, and particularly of the critical ferromagnetic behavior. We use modified Arrott plot technique to establish critical exponents b, g, and d of this alloy. We find that at low Mn concentrations (< 10 at.%), it is governed by short-range 3D-Ising behavior, with experimental values of b, g, and d very close to theoretical 3D-Ising values of 0.325, 1.24, and 4.815. However, as the Mn concentration increases, this DMS material exhibits a mixed-phase behavior, with g retaining its 3D-Ising characteristics, but b crossing over to longer-range mean-field behavior.

arXiv comment28 pages, 6figures, 1 table

References in corpus (15)

• Spintronics: Fundamentals and applications
• Ferromagnetism in semiconductors and oxides: prospects from a ten years' perspective
• Tricritical Point and the Doping Dependence of the Order of the Ferromagnetic Phase Transition of La1-xCaxMnO3
• Roadmap for Emerging Materials for Spintronic Device Applications
• Theory of Mn-doped I-II-V Semiconductors
• Properties of single crystalline AZn2Sb2 (A=Ca,Eu,Yb)
• Phase diagram and critical behavior of the random ferromagnet $G{a}_{1-x}M{n}_{x}N$
• (Ca,Na)(Zn,Mn)2As2: a new spin & charge doping decoupled diluted ferromagnetic semiconductor with hexagonal CaAl2Si2 structure
• Local atomic and magnetic structure of dilute magnetic semiconductor (Ba,K)(Zn,Mn)${}_2$As${}_2$
• (Sr,Na)(Zn,Mn)2As2: A new diluted ferromagnetic semiconductor with the hexagonal CaAl2Si2 type structure
• Ba(Zn,Co)2As2: a II-II-V Diluted Ferromagnetic Semiconductor with N-type Carriers
• A substantial increase of Curie temperature in a new type of diluted magnetic semiconductors via effects of chemical pressure
• Critical behavior of diluted magnetic semiconductors: the apparent violation and the eventual restoration of the Harris criterion for all regimes of disorder
• Specific heat study of Ga1-xMnxAs
• Crossover critical behavior of Ga1-xMnxAs