Maki analysis of spin-polarized tunneling in an oxide ferromagnet

Spin-polarized tunneling data on ${\mathrm{La}}_{2/3}{\mathrm{Sr}}_{1/3}{\mathrm{MnO}}_3{/\mathrm{S}\mathrm{r}\mathrm{T}\mathrm{i}\mathrm{O}}_3/\mathrm{A}\mathrm{l}$ junctions have been analyzed in terms of numerical solutions to Maki’s equations which include the effects of orbital depairing, the Zeeman splitting of the spin states, and spin-orbit scattering. We show that there are two solutions to these equations, and identify the correct solution. High quality fits to the data with these solutions yield a ${\mathrm{La}}_{2/3}{\mathrm{Sr}}_{1/3}{\mathrm{MnO}}_3$ spin polarization of $P=+72.0\mathrm{}\pm 1\%.$