Substitution Effect of Sr for Ba of High-Tc Superconducting YBa2Cu3O7-y Ceramics

Wada, Takahiro; Adachi, Seiji; Mihara, Toshihiro; Inaba, Ritsuo

doi:10.1143/jjap.26.l706

Cited by 70 publications

(17 citation statements)

References 3 publications

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“…For x = 0.50 it again decreases in agreement with earlier studies [2][3][4][5][6]. However, small impurity phases arises in x = 0.50 composition as increasing Sr content results in an unstable 123 phase.…”

Section: Resultssupporting

confidence: 90%

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Magnetization and magneto-resistance in Y(Ba_1−xSr_x)₂Cu₃O_7−δ(x= 0.00–0.50) superconductors

Liyanawaduge

Singh

Kumar

et al. 2012

Supercond. Sci. Technol.

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Here we present the magnetic properties and upper critical field (B C2 ) of polycrystalline Y(Ba 1-x Sr x ) 2 Cu 3 O 7- superconductors, which are being determined through detailed ac/dc susceptibility and resistivity under magnetic field (RTH) study. All the samples are synthesized through solid state reaction route. Reduction in Meissner fraction (the ratio of field cooled to zero field cooled magnetization) is observed with increasing Sr content, suggesting occurrence of flux pining in the doped samples. The ac susceptibility and resistivity measurements reveal improved grain couplings in Sr substituted samples. Consequently the inter-grain critical current density (J c ), upturn curvature near the T c in temperature dependence of upper critical field [B C2 (T)], and B C2 are enhanced. Both J c and B C2 increase in lower Sr substitution (up to x = 0.10) samples followed by decrease in higher doping due to degradation in effective pining and grain coupling. PACS: 74.25.Wx, 74.25.fc, 74.25.Sv, 74.25.Op

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Section: Resultssupporting

confidence: 90%

“…It can be observed that doped samples consist of slightly smaller grains than pristine sample in agreement to ref. [6]. Also the doped samples show better surface texture with lower level of porosity than pristine sample.…”

Section: Resultsmentioning

confidence: 90%

Magnetization and magneto-resistance in Y(Ba_1−xSr_x)₂Cu₃O_7−δ(x= 0.00–0.50) superconductors

Liyanawaduge

Singh

Kumar

et al. 2012

Supercond. Sci. Technol.

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“…The c lattice parameter of the xϭ0.0 sample is smaller than that of a pure Y:123 compound without Sr substitution, in agreement with the results reported on similar samples. 21,23,24 The decreased c lattice parameter substantiates the substitution of a smaller ionic size Sr atom at the Ba site in the system. With increasing Pr concentration x, the orthorhombicity of the system decreases.…”

Section: Resultsmentioning

confidence: 72%

“…%. 21,23,24 Therefore, it is of interest to study Sr substitution in R:123, say, Y:123 along with simultaneous Pr substitution at the R site. In this article we report our findings on the superconductivity, magnetism, and structural aspects of the Y 1Ϫx Pr x Ba 1.5 Sr 0.5 Cu 3 O 7Ϫ␦ system.…”

Section: Introductionmentioning

confidence: 99%

Superconductivity and magnetism in the system Y1−xPrxBa1.5Sr0.5Cu3O7−δ (0⩽x⩽1.0)

Jhans

Malik

Awana

et al. 1997

Journal of Applied Physics

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The results of superconducting and magnetic studies on the Y1−xPrxBa1.5Sr0.5Cu3O7−δ system with 0⩽x⩽1.0 are reported. Superconducting transition temperature (Tc) decreases with increasing x. The behavior of Tc(x)/Tc(0) versus Pr concentration x in this system is similar to that observed in the Y1−xPrxBa2Cu3O7−δ system but the critical Pr concentration (xcr) required for complete suppression of superconductivity appears to be higher in the present system. Surprisingly, the Néel temperature TN of PrBa1.5Sr0.5Cu3O7−δ is found to be higher (∼21 K) than that for PrBa2Cu3O7−δ (∼17 K) with nearly the same oxygen content. This may imply stronger interaction of Pr-4f moments with the carriers in the Cu–O2 planar network in the present system and yet the Tc suppression is relatively weaker.

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“…The Sr doping, however, scarcely increases T c for Y124 [4], or remarkably decreases T c for YBa 2 Cu 3 O 7−δ [14][15][16][17][18], although the unit cell volume shrinks (the unit cell volume of Y124 with Sr of x=0.3 corresponds to that under an external hydrostatic pressure of about 2.4 GPa [19]). Hence, one can suspect randomness effect on the actual T c .…”

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confidence: 99%

Cu nuclear quadrupole resonance study of site disorder and chemical pressure effects onY(Ba1−xSrx
Itoh
¹
,
Adachi
²
,
Machi
³

et al. 2001
Phys. Rev. B
10
0
8
0
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We report a zero-field Cu nuclear quadrupole resonance (NQR) study on the effects of nonmagnetic Sr substitution for high-Tc superconductors, Y(Ba1−xSrx)2Cu4O8 (Tc=82-80 K for x=0-0.4), using a spin-echo technique. The site-disordering and chemical pressure effects associated with doping Sr were observed in the broadened, shifted Cu NQR spectra. Nevertheless, the site disorder did not significantly affect the homogeneity of Cu electron spin dynamics, in contrast to the in-plane impurity. The peak shift of Cu NQR spectrum due to Sr was different between the chain-and the plane-Cu sites, more remarkably than those under a hydrostatic physical pressure, suggesting anisotropic or nonuniform local structural strains. The small decrease of Tc due to Sr can be traced back to either a cancellation effect on Tc between the disorder and the pressure, or an anisotropic or nonuniform chemical pressure effect on Tc. The role of imperfections in quantum many-body systems has attracted strong attention [1,2]. In high-T c cuprate superconductors, an additional impurity potential is introduced through the in-plane or out-of-plane element substitution for the CuO 2 plane. There is a belief that site disorder does not cause serious damage to the electronic states of the CuO 2 plane. However, the reason why chemical pressure effect on T c due to the element substitution is not the same as the physical (external) pressure one has been frequently ascribed to the randomness effect. How the site disorder changes the electronic states has been a problem.Here, we focus on the divalent Sr 2+ -doped high-T c superconductors, Y(Ba 1−x Sr x ) 2 Cu 4 O 8 . Since the stoichiometric and naturally underdoped YBa 2 Cu 4 O 8 (Y124) with T c =82 K has the exceptionally tight oxygen content, the Sr-doped Y124 is a suitable system to study the site-disordering effect on the electronic states. To be exact, one can expect two effects of Sr substitution for Ba in Y124 without change of oxygen content; (1) the chemical pressure and (2) the crystalline potential disorder. The substitution of Sr 2+ ions causes no additional local (formal) charge in Ba 2+ O 2− layers. However, the size of Sr 2+ ion is smaller than that of Ba 2+ by about 10 % [3], so that the substituted Sr ions make local crystalline strains on the BaO layers. Thus, the Sr doping introduces crystalline potential disorder and chemical pressure to the lattice. Actually, the lattice constants shrink with doping Sr [4], being in parallel to the physical pressure effect [5].The effect of hydrostatic physical pressure on the spin dynamics is similar to the carrier doping effect [6][7][8]:The physical pressure effects on T c and on the pseudo spin-gap temperature T s agree with the carrier doping effects, i.e. with applying the physical pressure to Y124 (T c =82 K and T s ∼160 K at an ambient pressure P =0

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Substitution Effect of Sr for Ba of High-T_c Superconducting YBa₂Cu₃O_7-y Ceramics

Cited by 70 publications

References 3 publications

Magnetization and magneto-resistance in Y(Ba_1−xSr_x)₂Cu₃O_7−δ(x= 0.00–0.50) superconductors

Magnetization and magneto-resistance in Y(Ba_1−xSr_x)₂Cu₃O_7−δ(x= 0.00–0.50) superconductors

Superconductivity and magnetism in the system Y1−xPrxBa1.5Sr0.5Cu3O7−δ (0⩽x⩽1.0)

Cu nuclear quadrupole resonance study of site disorder and chemical pressure effects onY(Ba1−xSrx
Itoh
¹
,
Adachi
²
,
Machi
³

et al. 2001
Phys. Rev. B
10
0
8
0
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Substitution Effect of Sr for Ba of High-Tc Superconducting YBa2Cu3O7-y Ceramics

Cited by 70 publications

References 3 publications

Magnetization and magneto-resistance in Y(Ba1−xSrx)2Cu3O7−δ(x= 0.00–0.50) superconductors

Magnetization and magneto-resistance in Y(Ba1−xSrx)2Cu3O7−δ(x= 0.00–0.50) superconductors

Superconductivity and magnetism in the system Y1−xPrxBa1.5Sr0.5Cu3O7−δ (0⩽x⩽1.0)

Cu nuclear quadrupole resonance study of site disorder and chemical pressure effects onY(Ba1−xSrxItoh1, Adachi2, Machi3 et al. 2001Phys. Rev. B10080View full textAdd to dashboardCite

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Substitution Effect of Sr for Ba of High-T_c Superconducting YBa₂Cu₃O_7-y Ceramics

Magnetization and magneto-resistance in Y(Ba_1−xSr_x)₂Cu₃O_7−δ(x= 0.00–0.50) superconductors

Magnetization and magneto-resistance in Y(Ba_1−xSr_x)₂Cu₃O_7−δ(x= 0.00–0.50) superconductors

Cu nuclear quadrupole resonance study of site disorder and chemical pressure effects onY(Ba1−xSrx
Itoh
¹
,
Adachi
²
,
Machi
³

et al. 2001
Phys. Rev. B
10
0
8
0
View full text Add to dashboard Cite