Abstract

We report the electronic, elastic, mechanical, optical and magnetic properties of Rh2MnX (X=Ti, Hf, Sc, Zr, Zn) Heusler alloys performed within density functional theory (DFT). The generalized gradient approximation (GGA) was used for calculations in the context of the Perdew-Burke-Ernzerhof (PBE) exchange-correlation energy treatment. The computed elastic constants and elastic moduli show that all investigated alloys are mechanically stable and ductile. It has been found that the magnitudes of the theoretical Vickers hardness values of these alloys are in the range of Ti> Sc> Zr> Hf> Zn. Also, a typical metallic behavior is obtained for all alloys after agreement of mechanical, electronic and optical data. On the other side, all alloys show strong ferromagnetic ordering following the magnetic moment (µB) rank of Ti > Zr > Hf > Sc > Zn. Our calculated µB data also agree well with the former theoretical results of Rh2MnX (X=Ti, Hf, Sc, Zr, Zn) Heusler alloys.
Keywords : Full Heusler; electronic; elastic; magnetic; optical; DFT.
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Introduction
After their discovery by F. Heusler [1,2] in 1903, Heusler alloys became an indispensable group of materials for rapidly developing technology with their widespread use [3-10]. For example, they are excellent candidates for spintronics, shape memory alloys, ferroics, magneto-caloric materials, skyrmions, etc. [11]. In general, Heusler alloys classify into four main structural groups as full Heusler alloys, half Heusler alloys, inverse Heusler alloys and quaternary Heusler alloys [11]. From them, two main groups of Heusler alloys exist with face-cantered cubic crystal structure with composition ranges of XYZ (half-Heusler) or X2YZ (full Heusler), where X and Y are transition metals and Z is a p-block element the periodic table. Besides, inverse Heusler alloys emerge with the formula X2YZ where Y element has a larger valence than the X element exhibiting Slater-Pauling behavior [12, 13]. In the last category, quaternary Heusler alloys have the form of XX’YZ and composed of different transition elements where the valence of X is higher than the valence of X’ which is higher than the valance of Y.
Because of their remarkable properties, all four groups of Heusler alloys have been subjected to many diverse theoretical studies up to date [14-20]. However, although much efforts have been spent on different types of Heusler alloys [21-24], it is still necessary to clarify and understand the basic physical aspects of these alloys. Despite the Rh2MnX (X=Ti, Hf, Sc, Zr, Zn) novel magnetic Heusler alloys are first reported by Stefano et al. [25] in 2017, there are still only a few studies [26, 27-28] on these alloys. So, in this work, we focused on the electronic, elastic, mechanical, optical and magnetic properties of (X=Ti, Hf, Sc, Zr, Zn) Heusler alloys to contribute to the lacking literature of Rh2MnHf, Rh2MnSc, Rh2MnSc, Rh2MnzZr and Rh2MnZn Heusler alloys.
Hereafter, we present the computational details of this work in Section 2. As well, Section 3. of the paper imparts the result and discussion part in detail where Section 4. yields and summarizes the important findings of our work with conclusions. As far as we know, this is the first detailed theoretical work performed on the electronic, elastic, mechanical, optical and magnetic properties of Rh2MnX alloys. Therefore, this study may be useful for the scant experimental researches of these alloys in the next future.