On the nature of magnetic state in the spinel Co2SnO4

• In the spinel Co2SnO4, coexistence of ferrimagnetic ordering below T-N similar or equal to 41K followed by a spin glass state below T-SG similar or equal to 39K was proposed recently based on the temperature dependence of magnetization M(T) data. Here new measurements of the temperature dependence of the specific heat C-P(T), ac-susceptibilities chi'(T) and chi ''(T) measured at frequencies between 0.51 and 1.2 kHz, and the hysteresis loop parameters (coercivity H-C(T) and remanence M-R(T)) in two differently prepared samples of Co2SnO4 are reported. The presence of the Co2+ and Sn4+ states is confirmed by x-ray photoelectron spectroscopy (XPS) yielding the structure: Co2SnO4 = [Co2+][Co2+Sn4+]O-4. The data of C-P versus T shows only an inflection near 39K characteristic of spin-glass ordering. The analysis of the frequency dependence of ac-magnetic susceptibility data near 39K using the Vogel-Fulcher law and the power-law of the critical slowing-down suggests the presence of spin clusters in the system which is close to a spin-glass state. With a decrease in temperature below 39K, the temperature dependence of the coercivity H-C and remanence M-R for the zero-field cooled samples show both H-C and M-R reaching their peak magnitudes near 25 K, then decreasing with decreasing T and becoming negligible below 15K. The plot of C-P/T versus T also yields a weak inflection near 15 K. This temperature dependence of HC and remanence MR is likely associated with the different magnitudes of the magnetic moments of Co2+ ions on the 'A' and 'B' sites and their different temperature dependence.

Subject headings

NATURVETENSKAP  -- Fysik -- Den kondenserade materiens fysik (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences -- Condensed Matter Physics (hsv//eng)

Keyword

ferrimagnetism

spin-glass

spinels

Teknisk fysik med inriktning mot fasta tillståndets fysik

Engineering Science with specialization in Solid State Physics

Publication and Content Type

ref (subject category)

art (subject category)