Preparation of (TiTe 2 ) x (Sb 2 Te 3 ) y (TiTe 2 ) 3 (Bi 2 Te 3 ) z Superlattices using the Modulated Elemental Reactants (MER) Technique

Difficulty in preparing (Bi2Te3)x(Sb2Te3)y superlattices due to interdiffusion of Sb and Bi led to the study of interduffusion barriers. TiTe2 has been explored as an interdiffusion barrier to minimize the interdiffusion of Sb and Bi, as TiTe2 is not soluble in either Bi2Te3 or Sb2Te3. Preparation of (TiTe2)3(Sb2Te3)y(TiTe2)3(Bi2Te3)z superlattices has been achieved with varying x, y and z. The formation of the superlattices was studied as a function of annealing temperature and time. TOF-SIMS depth profiles were used to study the extent of interdiffusion in the samples. Unit cell control was achieved allowing for the preparation of an array of superlattices with varying periods with very good reproducibility.