Spin-freezing behaviors in the layered perovskiteSr3V2

Abstract

We have examined electrical and magnetic properties of the Sr3V207d system. Electrical resistivity changes from metallic to semiconducting with decreasing oxygen content. Transport is governed by variable-range hopping of the electrons since the resistivity obeys the exp(AT '~) law at low temperature. Oxygen-deficient Sr3V207d exhibits different temperature-magnetic susceptibility curves for zero-field-cooled and field-cooled measurements below about 15 K. We have measured also the field dependence of the magnetic susceptibility and the long-time relaxation of thermoremanent magnetization, which obeys the relationship MTRM=At . The magnetic properties in the Sr3V207d system, therefore, are interpreted to be spin-glass-like, caused by the localized V spins introduced by the disorder-induced localization.Copper-based high-T, oxides have certain common features, such as a two-dimensional crystal structure, a -, ' spin on the Cu + ion, and the existence of the "parent" antiferromagnetic insulators, which are considered to be clues both to elucidating the mechanism for high-T, superconductivity and to searching for other high-T, super-

Magnetic properties of Ni2+ clusters in NaY zeolite

“…4. 17 This type of branching in the ZFC and FC magnetization curves and peak in the ZFC magnetization curve are common observations in a variety of magnetic materials like randomly canted ferromagnets, 18,19 spin glasses, [20][21][22] cluster spin glasses, 23 However, Horikawa et al 10 explained that the branching in the ZFC and FC magnetization curves with a peak in the ZFC magnetization curves at ϳ9 and 4 K for their Ni exchanged zeolites A and X, respectively, is due to spin-glass behavior of their samples. M ZFC ͑T͒ curves show a little upturn when we further decrease the temperature sufficiently below the T peak .…”

Magnetic Properties of Sr₃V₂O₇

“…Since they are the end members of the homologous series of Ruddlesden-Popper (RP) phase as seen in Fig show similar magnetic behavior; their magnetic susceptibility (χ) is almost temperature (T) independent above 200 K and 100 K, respectively, and drops steeply below the temperatures owing to antiferromagnetic ordering 9,15) . By contrast, Sr 3 V 2 O 7 is metallic [16][17][18][19][20][21][22] . Weak Curie-Weiss behavior, a small kink at around 110 K, and thermal hysteresis below around 30 K were seen in its χ-T curve [17][18][19]21,22) .…”

“…By contrast, Sr 3 V 2 O 7 is metallic [16][17][18][19][20][21][22] . Weak Curie-Weiss behavior, a small kink at around 110 K, and thermal hysteresis below around 30 K were seen in its χ-T curve [17][18][19]21,22) . Because of these features, the magnetic ground state has been thought to be a spin-glass state or a canted antiferromagnetic ordered state [17][18][19]21,22) .…”

“…Weak Curie-Weiss behavior, a small kink at around 110 K, and thermal hysteresis below around 30 K were seen in its χ-T curve [17][18][19]21,22) . Because of these features, the magnetic ground state has been thought to be a spin-glass state or a canted antiferromagnetic ordered state [17][18][19]21,22) . A theoretical work suggests that the kink is due to a charge-or spin-wave-density formation due to hidden one-dimensionality 23) .…”

“…Reducing in flowing hydrogen gas at 900-1100°C resulted in Sr 3 V 2 O 7-δ (δ = −0.01, 0.27, and 0.31) 18,21) . is negligible because it is the salt of VO 4 4− oxoanions.…”