Structure and magnetotransport properties of Cd3As2 crystals synthesized via horizontal gas-transport method from non-stoichiometric precursor

Abstract

In this work we investigated correlation of the structure and magnetotransport properties of Cd${}_3$As${}_2$ crystals with growth conditions in the framework of horizontal gas-transport method. As a precursor we used crystal with non-stoichiometric ratio of elements, which resulted in the formation of small amount of CdAs${}_2$ phase. We show that the latter can be used to obtain single phase Cd${}_3$As${}_2$ crystal at higher growth rates. Obtained data suggests that the increase of condensation temperature do not affect lattice parameters or mean crystallite size of the Cd${}_3$As${}_2$ phase, although it promotes the formation of the macroscopic defects. The latter increases observed resistivity values, without changing the relative amplitudes of its temperature and field dependences if the volume fraction of such defects remains constant. Carrier densities in studied crystals are substantially lower than typical values for crystals obtained from the melt. Estimated carrier mobility values are close for samples obtained at temperature below and above the ${\alpha }^{\prime \prime }-\beta$ polymorphic transition, suggesting its minor role in properties of crystals obtained via gas-transport method. Observed linear magnetoresistance is qualitatively identical in all studied samples, although its amplitude decreases along with carrier density.