Analysis of some non-linear effects in quantitative electron paramagnetic resonance spectrometry. Non-linear effects due to the use of cavities with TE102 and TM110 modes

The non-linear effects between the electron paramagnetic resonance (EPR) signal intensity and sample shape (length and diameter) and its positioning in the most commonly accepted cavities operating in TE102 or TM110 modes are discussed in detail. These effects are only due to the physical properties of the cavities. It is obvious from both theoretical considerations and experimental results that several precautions must be taken with respect to the physical parameters, like internal diameter of the sample tubes and length of the unknown sample and standard on planning quantitative EPR estimations.