Peculiarities of crystal structure and superfine interactions in alloys Ti-Co-Sn

S.O Yuryev,S.I Yushchuk,F.M Gonchar,O.M Gorina,V.V Moklyak,B.B Onyskiv

doi:10.15330/pcss.21.4.645-649

Abstract

Alloys with the general formula TiCo2-хSn were produced by way of sintering primary components – pure metals in an argon atmosphere. The alloys were homogenized by annealing in the evacuated quartz vessel at T=1070 K during 500 h. X-ray diffraction analysis confirmed single-phase condition of all samples. Nuclear gamma resonance (NGR) analysis was made at T=295 and 80 K using radiation source BaSn119Sn. It was established, that Sn atoms in samples with x=0.6 and 1.0 are in two crystallographic positions, pyramids (1) and tetrahedrons (2) to which isomer shifts correspond (relative to SnO2 1.52-1.65 mm/s for Sn(1) and 2.99 mm/s for Sn(2). Zeeman splitting for Sn(1) in TiCo2Sn takes place at T=295 and 80 K, and for compositions with x=0.3-1.0 at T=80 K only. For Sn(2) it is noted only in alloy TiCoSn at T=80 K. The conclusion has been made on the reason of formation of effective magnetic fields on non-magnetic tin atoms nuclei.

Highlights

There are known works, for example [1], where the alloys MeCo2Sn (Me = Ti, Zr, Hf) have been studied using NGR method
As of today there is still no clear understanding of the mechanism of formation of magnetic superfine interactions for the non-magnetic Sn atom in MeCo2Sn phases. This is why investigation of magnetic fields on tin atoms nuclei in isostructural alloys with MeCo2Sn phase is important for resolving this problem
This paper deals with the establishment of interrelation of the strength of magnetic field on tin atoms in solid solutions TiCo2-xSn and their composition and peculiarities of crystal structure

Summary

Introduction

There are known works, for example [1], where the alloys MeCo2Sn (Me = Ti, Zr, Hf) have been studied using NGR method Such alloys are attributed to Heusler phases whose magnetic and electric properties depend on the chemical nature of the element Me, and on the degree of their lattice perfection [2, 3]. This paper deals with the establishment of interrelation of the strength of magnetic field on tin atoms in solid solutions TiCo2-xSn and their composition and peculiarities of crystal structure. It is known, that alloys TiCo2-xSn form solid solutions whose homogeneity includes values x = 0.0...1.0 [4]. X-ray diffraction analysis has shown, that TiCoSn alloy has a crystal structure that is a defective derivative of TiCo2Sn alloy structure where Co atoms occupy only half of tetrahedral positions [6, 7]

Results

Discussion

Conclusion