Impact of lanthanum doping on crystal structure and magnetic anisotropy of Mn-Zn soft nanoferrites
Gaurav Katoch, Gazal Sharma, Vicky Jain, Asha Rajiv, Jacquline Tham, Ashish Kumar Singh, Vikas Kaushik, Teku Kalyani, Abhijit Bhowmik, A. Johnson Santhosh
Abstract
The synthesis of lanthanum (La) substituted Zn (Mn 0.6 Zn 0.2 La 0.2 Fe 2 O 4 ) and Fe (Mn 0.6 Zn 0.4 La 0.2 Fe 1.8 O 4 ) was performed using sol-gel auto-combustion techniques to investigate the effects of lanthanum doping on the structural and magnetic properties of Mn-Zn nanoferrites. X-ray diffraction and transmission electron microscopy confirmed the development of a single-phase spinel structure and a reduction in crystallite size (from 16 to 10.7 nm) with La substitution. Although saturation magnetization (M s ) decreased due to changes in cation distribution and magnetic interactions, La doping led to an increase in initial permeability. This enhancement was linked to changes in M s and the magneto-crystalline anisotropy constant (K 1 ). The permeability loss factor (tan δ µ ) remained low (around 10 − 2 ) for the La-doped ferrites, indicating minimal energy loss at room temperature. These results suggest promising potential for advanced biomedical applications, in line with Sustainable Development Goals (SDGs). The sol-gel auto-combustion technique provides a scalable and environmentally friendly method for synthesizing these materials, supporting SDG targets related to responsible consumption and production (SDG 12).