Magnetic Properties of some Anhydrous Chlorides of the Iron Group I: Magnetic Resonance

Measurements of paramagnetic resonance absorption in CrCl3 and NiCl2 in the temperature range 13.15°K to 293°K are reported. The height of the absorption curve decreases and the line width increases as the temperature is lowered through the region of the cryomagnetic anomalies in these salts The results are discussed in part II, where consideration of other experimental work suggests that the magnetic transition in these salts at low temperatures is essentially ferromagnetic rather than antiferromagnetic. FeCl2 and CoCl2 were also examined in the same temperature range but paramagnetic resonance was not observed.