Small bubble garnet films with collapse-field temperature coefficients ranging from -0.3 to about 0%/°C

It is confirmed that collapse-field temperature coefficients
\DeltaH_{o}(T)
of conventional YSmLuCaGeIG (SL) films varied in the range of -0.1 ∼ -0.3 %/°C in proportion to the molar ratio of Lu
2
O
3
/Sm
2
O
3
in the melt composition.
\DeltaH_{o}(T)
of the SL system was found to be limited in the range of -0.21 ∼ -0.3 %/°C when considering the lattice parameter matching between GGG substrates and films. To obtain garnet films with
\DeltaH_{o}(T)
of less than -0.2 %/°C, Er and Gd substituted garnet films were studied. YSmErGdLuCaGeIG films with
\DeltaH_{o}(T)
of -0.10 %/°C and an YSmErCaGeIG films of -0.06 %/°C were obtained. From the resulting of
\DeltaH_{o}(T)
and saturation magnetization temperature coefficient
\DeltaM_{s}(T)
, it was derived that
\DeltaM_{s}(T)
accounts for most of the
\DeltaH_{o}(T)
.