Study of dependence upon the magnetic field and transport current of the magnetoresistive effect in YBCO-based bulk composites

Balaev, D. A.; Prus, A G; Shaykhutdinov, K. A.; Gokhfeld, D. M.; Петров, М. И.

doi:10.1088/0953-2048/20/6/002

Cited by 28 publications

(14 citation statements)

References 25 publications

(44 reference statements)

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“…It is also seen that the resistance decreases with increasing t a . The computed R(H) dependencies qualitatively coincide with experimental curves of polycrystalline superconductors in low fields [6][7][8]. Fig.…”

Section: Theorysupporting

confidence: 73%

Superconductivity on Interfaces of Nonsuperconducting Granules La2CuO4 and La1.56Sr0.44CuO4

Быков

Terent’ev

Gokhfeld

et al. 2018

J Supercond Nov Magn

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Composite materials fabricated by annealing of nonsuperconducting ceramics La 2 CuO 4 and La 1.56 Sr 0.44 CuO 4 at 910° C during various time are investigated. Areas of superconducting La 1.85 Sr 0.15 CuO 4 phase arises at boundaries of contacting nonsuperconducting granules. The volume fraction of the superconducting phase increases with increasing the annealing time. A model describing the magnetic and transport properties of the samples at low magnetic fields is constructed. The magnetotransport characteristics of obtained samples at low magnetic fields (~ 100 Oe) are defined by a weak links network formed by superconducting areas. At high fields behavior of the system is defined by a magnetization of the disconnected superconducting islands. The average size of the superconducting areas has been estimated from an extended critical state model.

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Section: Theorysupporting

confidence: 73%

Superconductivity on Interfaces of Nonsuperconducting Granules La2CuO4 and La1.56Sr0.44CuO4

Быков

Terent’ev

Gokhfeld

et al. 2018

J Supercond Nov Magn

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“…where A and B are the fitting parameters independent of h. 50,65 According to the Bardeen-Stephen model, 66 the sample resistivity q varies with h as q(h) $ sin 2 (h), whereas, experimental studies published in the literature show that the best fits obtained are in the form of Eq. (2).…”

Section: Discussionmentioning

confidence: 99%

Organization of flux line system and voltage oscillations in superconducting MgB2

Kiliç

Olutaş

Kılıç

et al. 2011

Journal of Applied Physics

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The influence of bidirectional square wave (BSW) current on the evolution of the V-t curves was studied in a polycrystalline sample of MgB 2 . Regular sinusoidal-like voltage oscillations were observed at well-defined values of the amplitude (I BSW ) and period (P I ) of the BSW current, temperature, and external magnetic field. The voltage oscillations were interpreted mainly in terms of short-and long-range spatial correlations in a flux line system, relaxation effects, and the dynamic competition between pinning and depinning. The oscillating mode was also discussed in terms of sliding charge density waves associated with density fluctuations. Alternatively, the coupling between conventional thermally activated flux creep theory and annealing of the disordered states was considered as another possible mechanism in describing the voltage oscillations. Due to the complex interplay of pinning and driving forces, the oscillating mode is correlated to the drifting of flux lines, which are in motion, and it is assumed that the majority of flux lines try to traverse the sample, but do not leave it entirely. The symmetry in voltage oscillations was attributed to the equality between flux exit and entry along the sample edges. In this process, the majority of flux lines leave the sample and the direction of motion of flux lines reverses. During the oscillatory motion, we suggest that the interaction between flux lines and pinning centers may be elastic coupling in nature, because of rigidity of the flux line lattice in MgB 2 . Non-oscillatory behavior of V-t curves measured for BSW drive with low P I was attributed pre-dominantly to the effect of pinning on the distribution of the flux lines. The vortex capacitor model could be applied to explain the voltage decays in these V-t curves. However, the voltage decays associated with switching of I BSW to dc current (I dc ) were correlated to current-induced quenched disorder and to the glassy state relaxation. Further, angular dependence of voltage oscillations reveals that the anisotropic effects are nearly negligible on the evolution of V-t curves. It was shown that the voltage oscillations can be described well by an empirical expression V(t) $ sin(wt þ /), where w is the frequency and / is the phase angle. Finally, at well-defined values of I BSW and P I of BSW current, H, and T, it was argued that the MgB 2 sample behaves like a double-integrator.

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“…6 представлены зависимости R(T ) для исследуемого образца в области резистивного перехода для случаев H j и H ⊥ j. Резкий скачок сопротивления соответствует переходу в ВТСП-гранулах, а плавная часть зависимости R(T ) -переходу в подсистеме межгранульных границ [17,[24][25][26]. Видно, что различие зависимостей R(T ) для случаев H j и H ⊥ j имеет место в температурном диапазоне, соответствующем резистивному переходу в межгранульной среде, что наблюдалось ранее [7,10].…”

Section: результаты и обсуждениеunclassified

“…Известно, что гранулярные высокотемпературные сверхпроводники (ВТСП) демонстрируют анизотропию магнитосопротивления R(H) и резистивного перехода R(T ) при различной взаимной ориентации магнитного поля H и транспортного тока j (здесь и далее вектор j соответствует макроскопическому направлению тока, протекающего через образец) [1][2][3][4][5][6][7][8][9][10][11][12][13]. С одной стороны, это неудивительно, поскольку в классическом рассмот-рении Бардина-Стефена для сверхпроводников второго рода зависящее от угла θ = ∠H, j магнитосопротивле-ние пропорционально sin 2 θ [14].…”

Section: Introductionunclassified

Анизотропия Магниторезистивных Свойств Гранулярных Высокотемпературных Сверхпроводников Как Результат Сжатия Магнитного Потока В Межгранульной Среде

Семёнов¹,

Балаев²,

Почекутов³

et al. 2017

Физика Твердого Тела

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С целью выяснения причины известной анизотропии магниторезистивных свойств гранулярных высо-котемпературных сверхпроводников (ВТСП), связанной со взаимной ориентацией магнитного поля H и транспортного тока j, исследовано поведение гистерезисных зависимостей магнитосопротивления R(H) образца ВТСП иттриевой системы при перпендикулярной (H ⊥ j) и параллельной (H j) конфигурациях. На основании концепции эффективного поля в межгранульных границах (через которые туннелируют носители сверхпроводящего тока) проведен анализ гистерезисных зависимостей R(H). Величина параметра, характе-ризующего эффективную степень сжатия магнитного потока в межгранульной среде, для перпендикулярной конфигурации оказалась примерно в 2 раза больше, чем для параллельной. Такой подход хорошо объясняет наблюдаемую многими авторами анизотропию магниторезистивных свойств гранулярных ВТСП (включая и данные по температурным зависимостям сопротивления в области резистивного перехода).Исследование выполнено при финансовой поддержке РФФИ, Правительства Красноярского края, Краевого фонда наука в рамках научного проекта № 16-48-243018.

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Study of dependence upon the magnetic field and transport current of the magnetoresistive effect in YBCO-based bulk composites

Cited by 28 publications

References 25 publications

Superconductivity on Interfaces of Nonsuperconducting Granules La2CuO4 and La1.56Sr0.44CuO4

Superconductivity on Interfaces of Nonsuperconducting Granules La2CuO4 and La1.56Sr0.44CuO4

Organization of flux line system and voltage oscillations in superconducting MgB2

Анизотропия Магниторезистивных Свойств Гранулярных Высокотемпературных Сверхпроводников Как Результат Сжатия Магнитного Потока В Межгранульной Среде

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