X-ray effects in charge-ordered manganites: A magnetic mechanism of persistent photoconductivity

摘要

Charge-ordered manganites of composite Pr(1-x)(Ca(1-y)Sr(y))(sub x)MnO3 exhibit persistent photoconductivity when illuminated by x-rays. The authors review transport and x-ray diffraction data as functions of x-ray exposure, magnetic field, and temperature which shed light on the origin of this unusual behavior. The experimental evidence suggests that the mechanism primarily involves a ferromagnetic polarization of local spins by hot electrons generated by the x-rays.