Evidence of reentrant spin glass phase in graphite intercalation compound

1998

Phys. Rev. B

Self Cite

The magnetic phase transitions of stage-2 FeCl 3 graphite intercalation compound have been studied using superconducting quantum interference device dc and ac susceptibility measurements in the temperature range between 1.9 and 18 K. The temperature, frequency, and field dependence of aa Ј , aa Љ , cc Ј , and cc Љ clearlyshow that this compound undergoes two kinds of spin-glass phase transition at T SG (h) (Ϸ4.5-6.1 K) and T SG (l) (Ϸ2 -2.5 K), respectively. Both aa Љ and cc Љ have peaks at T SG (h) that shift to the low-temperature side with decreasing frequency. The spin-glass phase below T SG (h) may result from a competition between the antiferromagnetic XY -like Fe 3ϩ spins as the majority and the ferromagnetic Ising Fe 2ϩ spins as the minority. The absorption aa Љ has a peak at T SG (l) that shifts to the low-temperature side with decreasing frequency. No anomaly in cc Љ is observed at T SG (l) , indicating that only the XY components of spins contribute to this transition. The spin-glass transition below T SG (l) may result from a competition between the intraplanar nearest-neighbor antiferromagnetic and next-nearest-neighbor ferromagnetic intraplanar exchange interaction, which is responsible for a possible incommensurate in-plane spin structure at low temperatures. ͓S0163-1829͑98͒01725-1͔

Section: "L…mentioning

confidence: 99%

Spin-glass phases in stage-2FeCl3graphite intercalation compound

1998

Phys. Rev. B

Self Cite

“…The detail of the analysis on the T and f dependence of χ ′ and χ ′′ was described by our previous paper. 10 From these results it may be concluded that our system undergoes phase transitions at T c (≈ 8.7 K) and T RSG (≈ 3.3 K). The low temperature phase below T RSG is a RSG phase and the intermediate phase between T RSG and T c is a FM phase.…”

Section: A Magnetic Phase Transitions At Trsg and Tcmentioning

confidence: 55%

“…We used the same sample of stage-2 Cu 0.8 Co 0.2 Cl 2 GIC that was used in the previous papers. 10,11 The detail of the sample characterization and synthesis were presented there. The stoichiometry of this compound is described by C x Cu 0.80 Co 0.20 Cl 2 with x = 11.04 ± 0.02.…”

Section: Methodsmentioning

confidence: 99%

“…In this paper we report our experimental results on the nonequilibrium aging dynamics of the FM phase and the RSG phase in reentrant ferromagnet, stage-2 Cu 0.8 Co 0.2 Cl 2 graphite intercalation compound (GIC) using DC magnetization measurements. This system undergoes magnetic phase transitions at T RSG ≈ 3.30 K and T c ≈ 8.70 K. 10,11 We examine the aging behavior of this system using the zero-field-cooled (ZFC) magnetization measurements. The relaxation rate S ZF C (t) exhibits a peak at a characteristic time t cr below T c , indicating the occurrence of the aging phenomena both in the RSG phase and the FM phase.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Ageing dynamics of ferromagnetic and re-entrant spin glass phases in a stage-2 Cu_0.80Co_0.20Cl₂graphite intercalation compound

J. Phys.: Condens. Matter

2006

Self Cite

Ageing dynamics of a re-entrant ferromagnet stage-2 Cu(0.8)Co(0.2)Cl(2) graphite intercalation compound has been studied using DC magnetization measurements. This compound undergoes successive transitions at the transition temperatures T(c) (≈8.7 K) and T(RSG) (≈3.3 K). The relaxation rate S(ZFC)(t) exhibits a characteristic peak at t(cr) below T(c). The peak time t(cr) at constant t(w) shows a local maximum around 5.5 K, indicating a slow dynamics arising from a frustrated nature of the ferromagnetic phase. It drastically increases with decreasing temperature below T(RSG). The spin configuration imprinted at the stop and wait process at a stop temperature T(s) (

“…1 for the magnetic phase diagram). 6,7 The phase transitions occur at a RSG transition temperature (T RSG ) and a Curie temperature (T c ). The intermediate phase be- tween T c and T RSG is the FM phase and the low temperature phase is the RSG phase.…”

Section: Introductionmentioning

confidence: 99%

Effect of random disorder and spin frustration on the reentrant spin-glass and ferromagnetic phases in the stage-2Cu0.93Co0.07Cl2graphite intercalation compound near the multicr

2006

Phys. Rev. B

Self Cite

Stage-2 Cu0.93Co0.07Cl2 graphite intercalation compound magnetically behaves like a reentrant ferromagnet near the multicritical point (cMCP ≈ 0.96). It undergoes two magnetic phase transitions at TRSG (= 6.64 ± 0.05 K) and Tc (= 8.62 ± 0.05 K). The static and dynamic nature of the ferromagnetic and reentrant spin glass phase has been studied using DC and AC magnetic susceptibility. Characteristic memory phenomena of the DC susceptibility are observed at TRSG and Tc. The nonlinear AC susceptibility χ ′ 3 has a positive local maximum at TRSG, and a negative local minimum at Tc. The relaxation time τ between TRSG and Tc shows a critical slowing down: τ with x = 13.1 ± 0.4 and τ * 0 = (2.5 ± 0.5) × 10 −13 sec. The influence of the random disorder on the critical behavior above Tc is clearly observed: α = −0.66, β = 0.63, and γ = 1.40. The exponent of α is far from that of 3D Heisenberg model.