Fluence Dependent Modification of Spin Ice Physics in Ho₂Ti₂O₇ Thin Films

We investigate the effects of strain, substrate orientation, and disorder on spin ice physics in Ho₂Ti₂O₇ thin films grown on yttria-stabilized-zirconia substrates via pulsed laser deposition. Regardless of growth orientation, all films exhibit an inflated unit cell that is larger than the one previously identified for bulk. Transmission electron microscopy has revealed the presence of anti-disorder and growth defects within the films, with the (110) oriented films showing the least number of defects. Magnetization measurements show the expected anisotropy and saturation values associated with spin ice physics. Interestingly, only the (110) oriented films show the hallmark spin ice plateau in magnetization, and the strength of this plateau shows a clear trend with the laser fluence used during growth. This study demonstrates the importance of disorder in the modification of spin ice physics in thin films.