Intrinsic exchange bias in Zn${}_x$Mn${}_{3-x}$O${}_4$ ($x\le 1$) solid solutions

Abstract

Bulk specimens of the hetaerolite solid solution Zn${}_x$Mn${}_{3-x}$O${}_4$, with $x$ = 0, 0.25, 0.5, 0.75, and 1 have been prepared as homogeneous, phase-pure polycrystalline samples as ascertained by neutron diffraction measurements. Samples with $x$ = 0.25, 0.5, and 0.75 exhibit shifted magnetic hysteresis loops at low temperature, characteristic of exchange bias typically seen in magnetic composites. We propose that the unusual magnetic behavior arises as a result of a nanoscale mixture of ferrimagnetic and antiferromagnetic regions that are distinct but lack long-range order. While some glassy behavior is seen in AC magnetic measurements, its magnitude is not sufficient to account for the observed dramatic exchange bias. Furthermore, isothermal and thermoremanent magnetization measurements distinguish this material from a pure spin glass. The title system offers insights into the alloying of a ferrimagnet Mn${}_3$O${}_4$ with an antiferromagnet ZnMn${}_2$O${}_4$ wherein distinct magnetic clusters grow and percolate to produce a smooth transition between competing orders.

9 pages, 12 figures

References in corpus (3)

• Magnetodielectric coupling in Mn3O4
• Spin-phonon coupling in antiferromagnetic chromium spinels
• Magnetic phase evolution in the spinel compounds Zn${}_{1-x}$Co${}_x$Cr${}_2$O${}_4$

Cited by in corpus (5)

• Exchange bias effect in alloys and compounds
• Exchange bias and memory effect in Sr${}_2$FeCoO${}_6$
• Structural change and phase coexistence upon magnetic ordering in the magnetodielectric spinel Mn${}_3$O${}_4$
• Total scattering descriptions of local and cooperative distortions in the oxide spinel (Mg,Cu)Cr2O4 with dilute Jahn-Teller ions
• Evolution of magnetic properties in the normal spinel solid solution Mg(1-x)Cu(x)Cr2O4