Structural, Morphological, and Magnetic Properties of Ba, Sm Doped and Ba–Sm Co‐Doped BiFeO₃ Nanocrystalline Thin Films Deposited by a Spin Coating Method

Abstract

In the present work, the BiFeO 3 , Bi 0.9 Ba 0.1 FeO 3 , Bi 0.9 Sm 0.1 FeO 3 , and Bi 0.9 Ba 0.05 Sm 0.05 FeO 3 nanocrystalline thin films on Pt/TiO 2 /SiO 2 /Si (100) substrate are synthesized using the spin coating method, and the structural, morphological, and magnetic properties are systematically investigated. The X-ray diffraction studies reveal that BiFeO 3 , Bi 0.9 Ba 0.1 FeO 3 , and Bi 0.9 Sm 0.1 FeO 3 films exhibit a polycrystalline distorted rhombohedra crystal structure and belong to the R3c space group, whereas, Bi 0.9 Ba 0.05 Sm 0.05 FeO 3 nanocrystalline film has shown a pure rhombohedral crystal structure. The grain size of the films is found to be 86, 75, and 63 nm for Bi 0.9 Ba 0.1 FeO 3 , Bi 0.9 Sm 0.1 FeO 3 , and Bi 0.9 Ba 0.05 Sm 0.05 FeO 3 , respectively. M−H measurements show that the magnetization considerably increases with Ba and Sm doping, and the highest magnetization is found to be 29 and 22 emu cm −3 at 10 and 300 K, respectively, in Bi 0.9 Sm 0.1 FeO 3 film. Further, the blocking temperatures are found to be 100, 150, 130, and 50 K for BiFeO 3 , Bi 0.9 Ba 0.1 FeO 3 , Bi 0.9 Ba 0.05 Sm 0.05 FeO 3 , and Bi 0.9 Sm 0.1 FeO 3 , respectively. IntroductionBiFeO 3 is one of the above room-temperature multiferroic materials, which shows ferroelectric (T C ≈ 830 °C) and magnetic transition (T N ≈ 370 °C) temperatures. This material has been encouraged for the fabrication of non-volatile ferroelectric randomaccess memory, sensors, and microactuators due to the leadfree and environmentally friendly. [1][2][3][4] Nowadays, people are also looking toward photovoltaic [5] and photocatalysis [6] applications. However, this BiFeO 3 has the serious limitation of low magnetic moment and weak magnetoelectric coupling due to the