Electric Quadrupole Interaction of 111Cd in Semiconductors

Abstract

The time differential perturbed angular correlation technique was applied to study the electric quadrupole interaction in various semiconductors. The quadrupole coupling of 111Cd in the InX and In2X3 compounds (X = S, Se, Te) are reported. In the orthorhombic InS we observed one quadrupole frequency which increases lineary with temperature. The behaviour is the same in InTe. In InSe, however, the electric field gradient (EFG) scales with a T3/2 power law, well known from former investigations in metals and semimetals. The strength of the interaction decreases from InS to InTe. The In2X3 semiconductors show several modifications. In2S3 exists in three phases and has been investigated in the temperature range 25 K ≤ T ≤ 1200 K. In β-In2S3 (stable up to 693 K)two interaction frequencies have been observed. The high temperature modification γ-In2S3 shows one EFG. In cubic α-In2S3 no EFG could be measured. In2Se3 exists in four modifications. The different phases and transition temperatures are not definite yet. In the β-phase (stable between 473 K and 823 K) we observed two energetically equal structures with different interaction frequencies. Such a case has not yet been reported. In2Te3 has been investigated in the β-phase only. The observed interaction is temperature independent. While in metals and semimetals most data can be well described by a T3/2 -dependence, semiconductors show different results.