Published online by Cambridge University Press: 25 February 2011
We have used transmission electron microscopy to study the structure of Pb1-xEuxTe alloys grown by molecular beam epitaxy. We have observed ordered solid solutions of the Pb1-x EuxTe alloys as well as spinodal decomposition for 0.35≤x<0.75. The spinodal decomposition corresponds to a modulation of both the composition and the lattice spacing of the Pb1-x EuxTe alloy. These modulated structures have periodicities of ∼18Å along the <111> and <110> directions and indicate that the solid solution of Pb1-x Eux Te is unstable in this range of compositions.