Ordered phase formation in Sm-Ni thin film deposited on Cr(100) single-crystal underlayer

Yusuke Hotta,Masaaki Futamoto,Makoto Yamada,Nobuyuki Inaba,Mitsuru Ohtake,Fumiyoshi Kirino,Takato Yanagawa

doi:10.1051/epjconf/20147504009

Abstract

Sm17Ni83 (at. %) alloy thin films are prepared on Cr(100) underlayers hetero-epitaxially grown on MgO(100) single-crystal substrates by employing an ultra-high vacuum molecular beam epitaxy system. The effect of substrate temperature on the ordered phase formation is investigated. The films deposited below 300 °C consist of amorphous phase, whereas formation of SmNi5 ordered phase is recognized for the films deposited above 400 °C. The SmNi5 films with ordered phase consist of two types of (110) variant whose c-axes are lying in the film plane and rotated around the film normal by 90° each other. With increasing the temperature from 400 to 500 °C, the long-range order degree increases from 0.65 to 0.80. The ordered film formed at 500 °C shows an in-plane magnetic anisotropy reflecting the magnetocrystalline anisotropy of SmNi5 crystal.

Highlights

Magnetic thin films with the uniaxial magnetocrystalline anisotropy energy (Ku) greater than 107 erg/cm3 and with the easy magnetization axis parallel to the substrate surface have been investigated for nanocomposite magnets
In our previous studies [7, 8], SmCo5 epitaxial films with the c-axes parallel and perpendicular to the substrate surface were respectively prepared on Cr and Cu underlayers by employing a molecular beam epitaxy (MBE) system equipped with a reflection high-energy electron diffraction (RHEED) facility
The in-plane X-ray diffrections (XRDs) confirms the formation of SmNi5 ordered phase and the epitaxial orientation relationship which are determined by RHEED

Summary

Introduction

Magnetic thin films with the uniaxial magnetocrystalline anisotropy energy (Ku) greater than 107 erg/cm and with the easy magnetization axis parallel to the substrate surface have been investigated for nanocomposite magnets. SmCo5 epitaxial films with the c-axis lying in in-plane have been prepared on MgO(100) [2–5] and MgO(110) [3–6] substrates by employing W [4], Cr [2, 3], and Fe [5, 6] underlayers. In our previous studies [7, 8], SmCo5 epitaxial films with the c-axes parallel and perpendicular to the substrate surface were respectively prepared on Cr and Cu underlayers by employing a molecular beam epitaxy (MBE) system equipped with a reflection high-energy electron diffraction (RHEED) facility. In-situ RHEED revealed the crystallographic property during film formation, which varied depending the substrate temperature and on the film thickness. The effects of substrate temperature and film thickness on the ordered phase formation are investigated

Experimental procedure

Results and discussion

Conclusion