HIGH FREQUENCY PARAMAGNETIC RESONANCE

The report describes a high frequency paramagnetic resonance spectrometer which was designed to operate at frequencies as high as 350 GHz, and its application to a number of specific material investigations. The spectrometer was designed and built during the initial year of this contract, and was applied initially in the study of CaF2 - Dy(2+). It was subsequently employed in studying the zero field split levels of TiO2 - Mn(3+), ZnWO4 - Ni(2+) and in attempts to observe and measure the zero field splitting of Fe(3+) in the hemoglobin molecule. This latter attempt has so far proven completely unsuccessful indicating that the splitting is considerably greater than 10/cm. Plans have also been formulated to utilize the spectrometer in studies of exchange and arisotropy effects in ferromagnetic, antiferromagnetic and ferrimagnetic materials where high frequency microwave studies may lead to a more complete understanding of these interactions. (Author)