SrRuO3 is a low temperature ferromagnet (Tc ≌ 150K) which has recently been investigated in thin film form due to its structural compatibility with other thin film perovskites materials of practical interest, including high-temperature superconductors. Magnetization studies of thin films of SrRuO3 deposited on cubic SrTiO3 indicate strong uniaxial anisotropy with the easy direction approximately along either the a or b axis, which are difficult to distinguish. The orthorhombic structure of SrRuO3 (a = 5.53, b = 5.57, c = 7.84 Å) has six symmetry-related orientations on the cubic substrate (a = 3.9Å). Using Lorentz transmission electron microscopy both the magnetic and the crystallographic domain microstructure are characterized.For TEM imaging the films are readily removed from the substrate by chemical etching, using a HF:HNO3:H2O etch of approximately 1:1:1 dilution. Free-floating SrRuO3 films of 300-1000Å in thickness are then supported on standard carbon/formvar films on Cu substrates.
Determination of the 3-D Magnetic Vector Potential using Lorentz Transmission Electron Microscopy
