Inverse population in a paramagnetic crystal produced as a result of thermal excitation of the spin system by a pulsed magnetic field
Vaisfel'd M. P., Imamutdinov F. S., Khasanov A. Kh.
A maser effect at the spin sublevels of Co2+, which is caused by direct conversion of the thermal energy of the crystal immersed in liquid helium in a coherent microwave radiation, has been observed for the first time in an experiment with a La2Mg3(N03)12.24H20 (LaMN) crystal with Co2+ and Ce3+ impurities.