Pyromagnetic infrared radiation detectors

Work on the spin reorientation transition in YbFeO3 was completed. This work showed the two second order transitions associated with the spin reorientation transition. Experimental work on 15 MHz on the family of materials (CoS(2-x)Se(x) has been completed. This study investigates the detector material limitations on high frequency response. In particular the effect of eddy currents is examined both theoretically and experimentally. Also, the effect of surface layers was studied when these materials unexpectedly showed a surface layer whose thickness depended on Se concentration. This surface layer had a transition temperature which was greater than the transition temperature of the bulk. In related work, statistical dynamic calculations are being made on the pyromagnetic response of a spin system coupled to a thermal reservoir in local equilibrium with a time and space temperature distribution satisfying Fourier's law when the reservoir is driven by an incident modulated radiation absorbed at the surface. Finally, work has also been completed on a pyromagnetic study of superconductors which use an induced moment effect.