A novel two microwave field ESR implemented by double field modulation

A theoretical and experimental study of the application of two microwave fields to the case of an inhomogeneously broadened electron spin resonance (ESR) line with neglect of spin diffusion is presented. The two microwave field ESR (TMFESR) may be implemented as a simple version of the double-modulation ESR method provided the modulation index is small. When applied to an inhomogeneously broadened ESR line, the technique yields a response whose width is twice the width of the spin packet. The E′ defect in γ-irradiated vitreous silica was studied by TMFESR yielding a value of T2=23.6 μs, in agreement with time-domain ESR measurements.