Superlattice domain engineering by pulsed laser deposition

Antiferromagnetic spintronics are considered to be a promising candidate for mitigating current rapid approach to semiconductor limitations. Antiferromagnets benefits from excellent robustness and terahertz frequency unlike its commonly used ferromagnet counterpart, while retaining the desired property to use electron spin as information carrier. Antiferromagnetic transition metal perovskites are of great interest in this regard for their highly dependent structure – functionality relation, especially in form of thin films for their substrate enabled strain engineering. In this work, we present our work in engineering of heterostructure superlattice in the (111)pc orientation on anisotropic strained substrate, in which displays orientation-selected relaxation and its related magnetic behaviour.

(La0.7Sr0.3MnO3/LaFeO3)x4/DyScO3(101)o superlattice is deposited by pulsed laser deposition with standard HF pre-treated DSO substrate for step-and-terrace finish. The as deposited super structure displayed uniform step-and-terrace as seen by atomic force microscope, that is fully strain from reciprocal space map (RSM) in Qx= (-1 0 1)o orientation. However, the super structure is seen to be relaxed in Qx=(0 1 0)o in RSM. Further investigation by 4D-STEM techniques revealed formation of structural domains with vertical domain walls separating two domains. The domains can be interpreted as double of unit cell which gives a second order Laue zone diffraction contrast in STEM. Further on, x-ray magnetic dichroism data from Advanced Light Source showing in-plane antiferromagnetic signature in ferromagnet hard axis and will be further discussed.