Magnetic Relaxation in Bi2Sr2Ca1Cu2O8+x Single Crystal

AbstractThe results of measurements of critical currents and magnetic relaxation on a Bi2 Sr2 Ca1 Cu2O8+x single crystal are reported. Activation energies for the flux motion have been determined from the temperature dependence of the critical current density and the time decay of the zero‐field‐cooled and the remanent magnetization. The effective activation energy increases with temperature, in agreement with the existence of a distribution of activation energies.

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Magnetic Relaxation and Flux Creep in Superconducting YBCO Thin Films

Modern Physics Letters B ◽

10.1142/s0217984903006104 ◽

2003 ◽

Vol 17 (20n21) ◽

pp. 1075-1080 ◽

Cited By ~ 2

Author(s):

Ali Ihsan Demirel

Keyword(s):

Thin Films ◽

Magnetic Relaxation ◽

Effective Activation Energy ◽

Chemical Deposition ◽

Activation Energies ◽

Organic Chemical ◽

Relaxation Data ◽

Broad Agreement ◽

Ybco Thin Films ◽

Metal Organic

In this work, the temperature dependence of the magnetic relaxation in samples of YBa 2 Cu 3 O 7 (YBCO) thin films of two different qualities grown on MgO by metal organic chemical deposition technique (MOCVD) is measured in the range of 4.2–80 K using an initial applied magnetic field of 0.1 T. The relaxation data are analyzed in terms of a single effective activation energy and then more correctly of a distribution of activation energies. The single activation energies extracted are in broad agreement with published results.

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Variation in Activation Energy and Nanoscale Characteristic Length at the Glass Transition

Chemistry Journal of Moldova ◽

10.19261/cjm.2008.03(1).17 ◽

2008 ◽

Vol 3 (1) ◽

pp. 31-43

Author(s):

Ion Dranca

Keyword(s):

Activation Energy ◽

Heat Capacity ◽

Glass Transition ◽

Effective Activation Energy ◽

Activation Energies ◽

Linear Size ◽

Effective Activation ◽

Scanning Calorimetry ◽

Clay System ◽

Heat Capacity Measurements

Differential scanning calorimetry has been used to study the α-relaxation (glass transition) in virgin polystyrene (PS), PS-clay nanocomposite, amorphous indomethacin (IM), maltitol (Mt) and glucose (Gl). Variation of the effective activation energy (E) throughout the glass transition has been determined by applying an advanced isoconversional method to DSC data on the glass transition. The relaxations have been characterized by determining the effective activation energies (E) and evaluating the sizes of cooperatively rearranging regions at the glass transition (Vg). The values of Vg have been determined from the heat capacity data. The α-relaxation demonstrates markedly larger values of E (~340 vs ~270 kJ mol-1) for the PS-clay system than for virgin PS. For IM in the glass transition region, the effective activation energy of relaxation decreases with increasing temperature from 320 to 160 kJ mol-1. In the Tg region E decreases (from~250 to ~150 kJ mol-1 in maltitol and from~220 to ~170 kJ mol-1 in glucose) with increasing T as typically found for the α-relaxation. It has been found that in the sub-Tg region E decreases with decreasing T reaching the values ~60 (glucose) and ~70 (maltitol) kJ -1 that are comparable to the literature values of the activation energies for the β-relaxation. Heat capacity measurements have allowed for the evaluation of the cooperatively rearranging region in terms of the linear size The PS-clay system has also been found to have a significantly larger value of Vg, 36.7 nm3 as compared to 20.9 nm3 for PS. Heat capacity measurements of IM have allowed for the evaluation of the cooperatively rearranging region (CRR) in term of linear size (3.4 nm) and the number of molecules (90). The size of CRR have been determined as 3.1 (maltitol) and 3.3 (glucose) nm.

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Correlating the axial Zero Field Splitting with the slow magnetic relaxation in GdIII SIMs

Chemical Communications ◽

10.1039/d0cc07474h ◽

2021 ◽

Author(s):

Júlia Mayans ◽

Albert Escuer

Keyword(s):

Magnetic Relaxation ◽

Zero Field ◽

Zero Field Splitting ◽

Field Splitting ◽

Slow Magnetic Relaxation

A possible relation between the value of the axial Zero Field Splitting and the occurrence of field-induced slow magnetic relaxation has been established for a new gadolinium(iii) compound.

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Time decay of the remanent magnetization in TDAE-C60

Physical Review B ◽

10.1103/physrevb.50.13051 ◽

1994 ◽

Vol 50 (17) ◽

pp. 13051-13053 ◽

Cited By ~ 20

Author(s):

R. Blinc ◽

P. Cevc ◽

D. Arčon ◽

D. Mihailovič ◽

P. Venturini

Keyword(s):

Remanent Magnetization ◽

Time Decay

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MAGNETIC RESISTIVITY IN Bi2Sr2Ca(Cu1-xCox)2Od EPITAXIAL THIN FILMS

International Journal of Modern Physics B ◽

10.1142/s0217979207035923 ◽

2007 ◽

Vol 21 (01) ◽

pp. 127-132

Author(s):

T. R. YANG ◽

G. ILONCA ◽

V. TOMA ◽

P. BALINT ◽

M. BODEA

Keyword(s):

Magnetic Field ◽

Thin Films ◽

Activation Energy ◽

Glass Transition ◽

Effective Activation Energy ◽

Epitaxial Thin Films ◽

Effective Activation ◽

High Quality ◽

Plastic Deformations ◽

Magnetic Resistivity

The scaling behavior of the effective activation energy of high-quality epitaxial c-oriented Bi 2 Sr 2 Ca ( Cu 1-x Co x)2 O d thin films with 0≤x ≤0.025 has been studied as a function of temperature and magnetic field. For all samples, the effective activation energy scales as U(T, μoH)=Uo(1-T/T c )mHn with exponent m=1.25±0.03, n=-1/2 and the field scaling 1/μoH and -UμoH for thick films and ultra thin films, respectively. The results are discussed taking into account of the influence of the Co substitution with a model in which U(T, H) arises from plastic deformations of the viscous flux liquid above the vortex-glass transition temperature.

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