Concentration-dependent electron spin resonance

A number of workers have studied the decrease of the intensity of a nuclear magnetic resonance (NMR) line as one adds impurities to the specimen. Usually the intensity of the line is (1-c)n, where c=the concentration of the impurities and n is the so-called wipe-out number, i.e., if the impurity is within a sphere containing n neighboring positions its effect is large enough so as to cause a nuclear quadrupole splitting of the host nuclei so that they no longer contribute to the NMR line. Experimentally one can determine n. The extension of this type of experiment into the domain of electron spin resonance (ESR), in a very simple way, is described. Also, the wipe-out number for Mn2+ in two systems, (Zn1-c+Cdc)S and Zn(S1-c+Sec), is measured. One finds n=157 and 270, respectively. © 1964 The American Physical Society.