Control of electrical leakage in magneto‐electric gallium ferrite via aliovalent substitution. Issue 12 (25th June 2019)

• Record Type: Journal Article
• Authors: Singh, Vijay; Brajesh, Kumar; Sahu, Sandeep; Garg, Ashish; Gupta, Rajeev
• Is Part Of: Journal of the American Ceramic Society. Volume 102:Issue 12(2019)
• Page Start: 7414
• Page End: 7427
• Publication Date: 2019-06-25
• Subjects: doping -- gallium ferrite -- leakage -- magnetoelectrics -- multiferroics; Ceramics -- Periodicals; 620.1405
• DOI: 10.1111/jace.16626
• Languages: English
• ISSNs: 0002-7820

Abstract

Abstract: One of the challenges with magnetoelectric multiferroic gallium ferrite (GaFeO3 or GFO) is its high electrical leakage whose control is essential for realizing any prospect of its practical applications. In this manuscript, we report on the effect of aliovalent doping at Fe site in magnetoelectric gallium ferrite in controlling its electrical leakage via tuning of its grain and grain‐boundary characteristics. Polycrystalline pure as well as zinc (Zn 2+ ) and zirconium (Zr 4+ )‐doped gallium ferrite samples were synthesized by conventional solid‐state reaction method. Contrary to defect chemistry predictions, Zn 2+ substituted samples show marked reduction in the electrical leakage with 10% Zn 2+ substituted samples showing two orders of magnitude lower leakage current while Zr 4+ ‐doped samples exhibit increased electrical leakage. This is supported by higher activation energy for conduction in the low frequency regime for Zn 2+ ‐doped samples while nearly temperature independent conduction for Zr 4+ ‐doped GFO samples. The results suggest that while Zn 2+ doping leads to increase in resistance of the grain boundaries leading to lower conductivity, Zr 4+ doping leads to opposite effect.