Low Magnetic Field Response of 2d-Array of Weakly Coupled Ferromagnets

Abstract

AbstractWe demonstrated a low magnetic field response in 2D array of weakly coupled ferromagnets created by bi-epitaxial growth of La0.7Sr0.3MnO3 film on multilayer template of MgO seed and CeO2 buffer layer deposited on SrTiO3 substrate. To form the array we etched the MgO seed layer into a chess board pattern. The chess board fields, where the substrate surface is disclosed, initiate a 45° in-plate rotated growth of the CeO2 buffer layer while it does not rotate on the neighboring fields covered by MgO seed layer. The La0.7Sr0.3MnO3 film inherits the template orientation of the buffer layer forming misoriented at 45° domains and a well defined 2D array of 45° grain boundaries is created. The size of the domains, correspondingly the number of grain boundaries, can be varied by changing the dimensions of the chess board fields. The multilayer structures were investigated by θ–2θ and φ-scan x-ray diffraction. A magnetoresistance of 25% by 0.5 T was measured and ascribed to the properties of the 2D array of grain boundaries.