⁹³Nb Nuclear Quadrupole Resonance in Orthorhombic Phase of Niobium Pentabromide

Abstract

The ⁹³Nb NQR has been investigated in one phase of NbBr₅ which was identified to be orthorhombic by the X-ray analysis. The resonance frequencies have been measured between 4.2 K and 423 K, its melting point. The coupling constant showed a positive temperature dependence up to melting point. The temperature dependence of the coupling constant is compared between NbBr₅ and NbCl₅ from the view point of π-bond character.