Investigation of MnxNi1-xO Thin Films Using Pulsed Laser Deposition

The exchange bias (EB) effect, especially in nanomaterials, is highly promising for use in antiferromagnet-based spintronics applications. NiO is a well known antiferromagnetic material with a high Néel temperature (525K) and can exhibit ferromagnetism/ ferrimagnetism by adding other magnetic transition elements. Our previous work has shown that the antiferromagnetic characteristics of conventional NiO insulating nanostructured material can be altered to have substantial ferrimagnetic characteristics by doping NiO with Mn or Co. Pulsed laser deposition (PLD) was used to grow heterostructures comprised of a nanostructured thin NiO film deposited on the surface of a MgO (100) and Al2O3 (111) substrates, followed by the deposition of a MnxNi1-xO thin film layer on top of the NiO layer. X-ray diffraction (XRD), scanning electron microscopy (SEM), and SQUID magnetometry were used to study the structural, morphological, and magnetic properties, respectively, of the thin film heterostructures. XRD and SEM characterizations show that the NiO/MnxNi1-xO bilayers were grown quasi-epitaxially on the MgO and Al2O3 substrates. The primary motivation of this study is to determine how the magnetic properties and the exchange bias effect may depend upon the interface morphology, structural characteristics and Mn concentration of the MnxNi1-xO layer in the heterostructures