About existence of hexadecapole interaction in spectrums NQR 115In in InSe

Abstract

Researchers assumed the existence of nuclear hexadecapole interaction of nuclei with a significant quadrupole moment long ago, but, unfortunately, there is no definiteness in the results. The scientific literature presents the direct experimental evidence only in some cases for the nuclei with large mass number, such as 127 I, 121 Sb, 123 Sb or 175 Lu . The problem of detection of this effect is that it is vanishingly small and, according to the researches, it is on the border of detectability of measuring equipment. Moreover, the situation is aggravated by the fact that this effect exists along with the high value of the quadrupole moment of the nuclei, which masks the occurrence of the hexadecapole interaction of small value. The purpose of the article is to prove the occurrence of the hexadecapole interaction in layered crystals with the strong anisotropy of the chemical bond, such as InSe. The presence of two-dimensional electronic structure of these crystals leads to the unusual physical properties, and the hexagonal crystal structure with axial symmetry makes these compounds perfect for studying the electronic distribution by the NQR method. The spectra NQR 115 In in InSe crystals, grown from the melt, and recorded by continuous method for four resonance transitions of 115 In with spin 9/2, were suggested. The multiplicity of spectra NQR with additional lines, which meet the forbidden transitions, was detected. It is believed, that this anomaly is caused by the presence of the hexadecapole interaction of nuclei 115 In with the electric field gradient in InSe