MnB Yumuşak Manyetik İnce Filmlerin Sentezi ve Karakteriasyonu

Abstract

In this study, manganese monoboride (MnB) thin films with soft ferromagnetic properties are fabricated by magnetron sputtering technique. Thin films are grown via two different techniques; co-sputtering and multilayer sputtering. MnxB100-x thin films with different thicknesses (75 nm and 500 nm) and atomic compositions varying in the range of x = 45 - 55 were produced to achieve the Mn50B50 structure. X-ray Photoelectron Spectroscopy (XPS) measurements have shown that 75 nm MnB thin film with 10 nm Ti capping layer is successfully synthesized at x = 50 at%. Magnetic properties of the as-made MnB thin films are determined by magnetic field-dependent magnetization [M(H)] and temperature-dependent magnetization [M(T)] measurements using Vibrating Sample Magnetometer (VSM). Results showed that 75 nm thick MnB thin films contain 7% B2O3 structure. Saturation magnetization and Curie temperature of the samples are found to be 760 emu/cc and 566 K, respectively. These values are in good agreement with the reported values of magnetic properties for bulk MnB in the literature. Synthesized 75 nm and 500 nm thick MnB films were annealed in-situ and ex-situ in order to get rid of the oxide structure and improve the magnetic properties by increasing crystallization. As a result of X-Ray Diffractometry (XRD) measurements, it was understood that thin films with 75 nm thickness which was annealed in-situ at 500 °C were not crystalline after annealing and still amorphous. The synthesized samples with 500 nm thickness were annealed at ex-situ to higher temperatures such as 800, 850 and 900 °C and as a result of this it was observed that the samples crystallized in XRD pattern but besides the desired phases, undesirable and undetectable phases were observed.