Orientation Relationships upon the Structural Transformation of Monoclinic and Cubic Phases in Silver Sulfide

Abstract

The orientation relationships between the low-temperature monoclinic semiconductor acanthite α-Ag₂S and the high-temperature body-centered argentite β-Ag₂S are determined based on high-temperature X-ray diffraction and high-resolution transmission electron microscopy (HRTEM) data on silver sulfide. It is found that, in contrast to acanthite, the possible distances between silver atoms in cubic argentite are too small to allow Ag atoms to occupy metal sublattice sites with a probability of 1. It is shown that the (010) and (001) atomic planes of acanthite are parallel to the (1\(\bar {1}\)0) and (221) planes of argentite, respectively. The found orientation relationships between acanthite and argentite are important for understanding the physical operation of the Ag₂S/Ag heteronanostructure, which is considered as a potential basis for designing resistive switches and nonvolatile memory devices.