Reentrant spin-glass behavior and bipolar exchange-bias effect in “Sn” substituted cobalt-orthotitanate

Journal Article · Thu Jan 28 00:00:00 EST 2016 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4940675· OSTI ID:22494935

Nayak, S.; Joshi, D. C.; Krautz, M.; Waske, A. ^[1]; Eckert, J. ^[2]

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1. Institute for Complex Materials, IFW Dresden, P.O. Box 270116, D-01171 Dresden (Germany)
2. Erich Schmid Institute of Materials Science, Jahnstrasse 12, A-8700 Leoben (Austria)

We report the co-existence of longitudinal ferrimagnetic behavior with Néel temperature T{sub N} ∼ 46.1 K and reentrant transverse spin-glass state at 44.05 K in Tin (Sn) doped cobalt-orthotitanate (Co{sub 2}TiO{sub 4}). The ferrimagnetic ordering is resulting from different magnetic moments of Co{sup 2+} on the A-sites (3.87 μ{sub B}) and B-sites (5.069 μ{sub B}). The magnetic compensation temperature (T{sub COMP}) shifts from 31.74 K to 27.1 K when 40 at. % of “Sn{sup 4+}” substitutes “Ti{sup 4+}” at B-sites where the bulk-magnetization of two-sublattices balance each other. For T > T{sub N}, the dc-magnetic susceptibility (χ{sub dc} = M/H{sub dc}) fits well with the Néel's expression for the two-sublattice model with antiferromagnetic molecular field constants N{sub BB} ∼ 15.44, N{sub AB} ∼ 32.01, and N{sub AA} ∼ 20.88. The frequency dependence of ac-magnetic susceptibility χ{sub ac} data follows the Vogel-Fulcher law, and the power-law of critical slowing-down with “zν” = 6.01 suggests the existence of spin-clusters (where “z” and “ν” being dynamic critical-exponent and correlation length of critical-exponent, respectively). This system exhibits unusual hysteresis loops with large bipolar exchange-bias effect (H{sub EB} ∼ 13.6 kOe at 7 K) after zero-field cooling process from an un-magnetized state, and a dramatic collapse of remanence (M{sub R}) and coercive field (H{sub C}) across T{sub COMP}. The possible origins of such anomalous characteristics were discussed.

• OSTI ID: 22494935
• Journal Information: Journal of Applied Physics, Vol. 119, Issue 4; Other Information: (c) 2016 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ANTIFERROMAGNETISM
BALANCES
COBALT
COBALT IONS
COOLING
CORRELATIONS
DOPED MATERIALS
FREQUENCY DEPENDENCE
HYSTERESIS
LENGTH
MAGNETIC MOMENTS
MAGNETIC SUSCEPTIBILITY
MAGNETIZATION
ORIGIN
SLOWING-DOWN
SPIN
SPIN GLASS STATE
TIN