Paramagnetic Resonance at Low Fields

Abstract

Paramagnetic resonance in 2,2-diphenyl-1-picrylhydrazyl and Wurster's Blue at very low values of applied magnetic fields has been investigated. The disappearance of the maximum of the absorption curve below frequencies of 1.3 megacycles has been substantiated. A twin-$T$ resonance spectrometer is described briefly. Line broadening with dilution of diphenylpicrylhydrazyl in benzene was investigated at 35 gauss and the second and fourth moments of the absorption curves calculated. These data show that the fourth moment increases more than the second moment as dilution is increased.