ABSTRACT
One may tackle the problem of creating strong gradients in the magnetic field from a somewhat different perspective. The creation of nonuniform fields with large gradients and known symmetry enables one to simplify significantly the analysis of spatial distributions. The dimension of paramagnetic impurity domains can be defined by using local nonuniform fields with large nonlinear gradients created by a "point" magnetic sphere. Since the electron paramagnetic resonance (EPR) signals in large gradient regions are severely broadened, only the narrower signals for centers located in the uniform field region are observed when the EPR spectra are recorded in this gradient. Another variant of employing local molecular gradients uses pulse EPR. The shape of the EPR spectrum was calculated for a continuous paramagnetic domain of size L oriented along the axis of a nonuniform field. The spatial resolution is 10 µm and is close to the ultimate resolution, limited by the sensitivity of the EPR method.
