| AVS 60th International Symposium and Exhibition | |
| Magnetic Interfaces and Nanostructures | Tuesday Sessions |
| Session MI-TuP |
| Session: | Magnetic Interfaces and Nanostructures Poster Session |
| Presenter: | O. Ozturk, Gebze Institute of Technology, Turkey |
| Authors: | M. Erkovan, Gebze Institute of Technology, Turkey M. Ozturk, Gebze Institute of Technology, Turkey E. Demirci, Gebze Institute of Technology, Turkey N. Akdogan, Gebze Institute of Technology, Turkey O. Erdemir, Gebze Institute of Technology, Turkey O. Ozturk, Gebze Institute of Technology, Turkey |
| Correspondent: | Click to Email |
In this study, we report EB effect observed in PtxCo1-x (x changes from 10 to 90 by 10 step)/ CoO bilayer thin films. PtCo alloys have very large magnetocrystalline anisotropy so they will be very good candidate for next generation data storage media. Besides EB effect is used in the read head sensors, so PtCo may find usage area in both the read head sensor and data storage media. Our goal was to determine how EB depends on Pt concentration in ferromagnetic PtCo layer and temperature.
All films were prepared at UHV conditions by magnetron sputtering deposition technique. The chemical ratios of PtCo layers and CoO layers for all composite films were characterized by Photoelectron Spectroscopy (XPS) technique. Quantum Design PPMS 9T vibrating sample magnetometer (VSM) was used to investigate EB properties of the films. Since the Néel temperature is about 290 K for antiferromagnetic CoO layer, PtxCo1-x /CoO films were heated up to 320K before cooling down to the measurement temperature to observe Exchange bias effect. An in-plane magnetic field of 2 kOe was applied while cooling the samples to the measurement temperatures.
Temperature-dependent magnetization measurements show that strength and onset temperature of exchange bias are enhanced by increasing Pt concentration. We observed also two different results from magnetization measurement. One of them is that the blocking temperature ( TB) of both samples is lower than the expected bulk value. The other one is that decreasing Pt concentration within the FM PtCo layer reduces TB to lower values. In order to determine the effect of Pt concentration on magnetic anisotropies, the samples have been investigated by using ferromagnetic resonance (FMR) technique at room temperature (RT). FMR experiments show uniaxial in-plane magnetic anisotropy at room temperature. This behavior becomes stronger when the Pt concentration is increased. According to these results, the manipulation of common interface between ferromagnetic and antiferromagnetic layers gives the possibility to tune the exchange bias with Pt concentration and temperature.