EPR OF EU2-XEUXSE LAYER AND IN PB1-XEUXSE( IN PB1)PBSE SUPERLATTICE GROWN BY MOLECULAR-BEAM EPITAXY ON BAF2 SUBSTRATES/

Electron paramagnetic resonance (EPR) experiments are performed at roo m and liquid helium temperature on layers Pb1-xEuxSe and on the superl attice PbSe/Pb1-xEuxSe, grown by molecular beam epitaxy. EPR measureme nts show unambiguously that Eu2+ ions replace the Pb2+ ions and that t he crystal field is associated with an octahedron of Se2+ ions in the Pb1-xEuxSe epitaxial layer. The data were fitted with the classical cu bic spin Hamiltonian. The crystal field coefficients are b(4)=267.4 MH z and b(6)=-3.4 MHz. Low-temperature experiments do not reveal the exi stence of strain in the epitaxial layers and in the superlattices. The effect of the europium concentration on the EPR spectrum can be chara cterized by (i) the vanishing of the fine structure, (ii) the appearan ce of a strong central transition, (iii) the broadening of the transit ion due to the Eu2+ nearest-neighbor dipolar and exchange interactions . [S0163-1829(98)03126-9].