SIMS accurate determination of matrix composition of topological crystalline insulator material Pb1 − xSnxSe

Substitutional alloy Pb1 - xSnxSe is a new class of electronic materials called topological crystalline insulators, which at the temperature range from 0 K to 300 K exhibit topological state at compositions in the range 0.18 x < 0.40 (in the rock-salt structure). In this report, we present a secondary ion mass spectrometry (SIMS) analysis technique to provide accurate Pb and Sn composition based on the measurement of PbCs+ and SnCs+ cluster ions intensities. Studies of Pb1 - xSnxSe bulk samples with various values of x show that x/(1 - x) is linear in relation to the intensity ratio of PbCs+/SnCs+ over the range from x = 0.15 to x = 0.41. This technique allows us to obtain an accurate Sn content for multilayered heterostructures, quantum wells containing Pb1 - xSnxSe with different x values for each layer.