No CrossRef data available.
Published online by Cambridge University Press: 11 February 2011
Epitaxial nickel zinc ferrite (Ni,Zn)Fe2O4 (NZF) thin films were successfully deposited on (MgO-Al2O3)/CeO2/YSZ/Si(001) substrates, where (MgO-Al2O3) is MgO doped with Al2O3. The crystallographic orientation and magnetic properties (saturation magnetization: Ms, and squareness: Mr/Ms where Mr is remanent magnetization) of NZF thin films were considerably changed with the amount of Al2O3 addition. If the amount of Al2O3 addition was less than 7 mol%, (001)-oriented epitaxial NZF thin films were obtained and the films had low squareness (around 45%). If the amount of Al2O3 addition was more than 7 mol%, (111)-oriented epitaxial NZF thin films were obtained and the films had high squareness (around 60–81%). Maximum squareness (81%) was obtained if the amount of Al2O3 addition was 26 mol%. For the sample with this Al2O3 content, the lattice mismatch between NZF and (MgO-Al2O3) buffer layer was 3.2%. The fact that high squareness was not obtained if lattice mismatch was very small (-0.3% on MgO) but obtained if lattice mismatch was 3.2% suggests that lattice mismatch to a certain content is important to avoid the formation of antiphase boundaries (APBs). This consideration was confirmed by examining other buffer layers having various lattice mismatches with NZF.