Epitaxial films of the low temperature modification of the compound Cu2Se

Epitaxial films of the low temperature modification of Cu₂Se deposited onto NaCl single-crystal substrates at 200°C and 400°C have been investigated. The diffraction pattern of this phase was indexed on the basis of a hexagonal lattice with unit cell parameters a = 7.07 and $\text{c = 6.68}\text{A}\text{?}$. These parameters are related to the parameters of the f.c.c. phase by the relations $\text{a}{}_{\mathrm{<mtext>h</mtext>}}\text{= (}\text{√3}\text{√2}\text{) a}{}_{\mathrm{<mtext>c</mtext>}}$ and $\text{c}{}_{\mathrm{<mtext>h</mtext>}}\text{= (}\text{2}\text{√3}\text{) a}{}_{\mathrm{<mtext>c</mtext>}}$.