Rapid oxygen diffusion in Cahyphen;doped yttrium iron garnet films at 25 to 250thinsp;deg;C

摘要

Unexpectedly rapid oxygen diffusion has been observed at 25ndash;250thinsp;deg;C in YIG films with uncompensated Ca additions of 0.1 to 0.23 atoms per formula unit. A 3hyphen;mgr;mhyphen;thick film originally dark and conducting due to Fe4+lightened and became insulating in 15 min at 100thinsp;deg;C in a reducing saturated solution of FeCl2. A diffusion distance of sim;0.5 mm has been observed along a film in 25 h at 250thinsp;deg;C. A model is proposed based on the dependence of the diffusion coefficientDon oxygen vacancy concentration. A magnetic bubble garnet film containing Ca, which also lightened at 250thinsp;deg;C, showed no observable changes in the pertinent bubble parameters.