Prediction of first-order martensitic transitions in strained epitaxial films

S Schönecker, M Richter, K Koepernik, H Eschrig
2015 New Journal of Physics  
Coherent epitaxial growth allows to produce crystalline films with strained structures which are unstable in the bulk. Thereby, the relationship between the lattice parameters of the overlayer in the interface plane, (a,b), and its minimum-energy out-of-plane lattice parameter, c_min(a,b), need not be continuous. This general statement is proven by examples of total energy calculations. As a consequence, c_min, which is determined by the choice of the substrate, and c_min-dependent intrinsic
more » ... perties of the overlayer cannot always be tuned in a continuous way as one may aim to do by means of strained epitaxy. Employing the model of the epitaxial Bain path we predict that such discontinuities occur in films of the elements V, Nb, Ru, La, Os, and Ir. The abrupt change of c_min can be exploited to switch properties specific to the overlayer material. This is demonstrated for the example of the superconducting critical temperature of a V film which we predict to jump by 20
doi:10.1088/1367-2630/17/2/023005 fatcat:4gpkupggwzbe7cnk6i6h5vszae