Investigation of the ultrasonic parameters of m-cresol and ethylene glycol as a function of the state parameters of the medium: Soviet Physics—Acoustics, Vol 14, No 1 (July–September 1968) pp 94–96 (1031)

Abstract

After nearly a century since the first synthesis of aluminum nitride (AlN), III-nitride semiconductors have become one cornerstone of modem optoelectronic and electronic devices thanks to a spectacular research and development in the last 20 years. The nitrides of group III metal elements commonly referred to as aluminum nitride (AlN), gallium nitride (GaN), indium nitride (InN), and their alloys, all of which are compounds of nitrogen—the smallest group V element in the Periodic Table and an element with one of the highest values of electronegativity. III-nitride semiconductors crystallize in their most stable form into a wurtzite crystallographic structure with nitrogen atoms forming a hexagonal close packed (hep) structure and the group III atoms occupying half of the tetrahedral sites available in the hep lattice. III-nitrides are polar crystals as they do not have a center of symmetry. They thus possess many other potentially useful properties such as piezoelectricity, pyroelectricity, and non-linear optical properties. Long regarded as a scientific curiosity, III-nitrides have now earned a most respected place in the science and technology of compound semiconductors, as well as modem electronic and optoelectronic devices.