Dilute ferrimagnetic semiconductors in Fe-substituted spinel ZnGa$_2$O$_4

• Main Authors: Risbud, A. S, Seshadri, R, Ensling, J, Felser, C
• Format: Journal Article
• Language: English
• Published: 06.04.2004
• Subjects: Physics - Materials Science
• DOI: 10.48550/arxiv.cond-mat/0404147

J. Phys.: Condens. Matter 17 (2005) 1003-1010. Solid solutions of nominal composition [ZnGa$_2$O$_4$]$_{1-x}$[Fe$_3$O$_4$]$_x$, of the semiconducting spinel ZnGa$_2$O$_4$ with the ferrimagnetic spinel Fe$_3$O$_4$ have been prepared with $x$ = 0.05, 0.10, and 0.15. All samples show evidence for long-range magnetic ordering with ferromagnetic hysteresis at low temperatures. Magnetization as a function of field for the $x$ = 0.15 sample is S-shaped at temperatures as high as 200 K. M\"ossbauer spectroscopy on the $x$ = 0.15 sample confirms the presence of Fe$^{3+}$, and spontaneous magnetization at 4.2 K. The magnetic behavior is obtained without greatly affecting the semiconducting properties of the host; diffuse reflectance optical spectroscopy indicates that Fe substitution up to $x$ = 0.15 does not affect the position of the band edge absorption. These promising results motivate the possibility of dilute ferrimagnetic semiconductors which do not require carrier mediation of the magnetic moment.