Control of carrier concentration in Bi-2212

S. Yamashita; T. Kasai; T. Fujii; T. Watanabe; A. Matsuda

doi:10.1016/j.physc.2009.11.065

Control of carrier concentration in Bi-2212

S. Yamashita^*, T. Kasai, T. Fujii, T. Watanabe, A. Matsuda

^*Corresponding author for this work

Research output: Contribution to journal › Article › peer-review

6 Citations (Scopus)

Abstract

We realized highly underdoped Bi-2212 crystals by using a Bi substitution into a Sr site (x), together with the excess oxygen (δ) control. The samples with x = 0-0.3 were grown by a traveling solvent floating zone method. For each x, δ was varied using the precision annealing method [1]. Under several assumptions, the effective Bi valence was evaluated to be +2.2, which is much lower than the formal valence +3. This indicates that the Bi substitution accompanies additional uptake in excess oxygen. The x dependent δ-doping level p relation and the observed shrink in the c-axis length are consistent with this assumption. Based on the decomposition phase diagram obtained in this study, T_c of 22 K was realized by careful annealing treatments. The samples showed a superconducting volume fraction of over 50%.

Original language	English
Pages (from-to)	S170-S172
Journal	Physica C: Superconductivity and its applications
Volume	470
Issue number	SUPPL.1
DOIs	https://doi.org/10.1016/j.physc.2009.11.065
Publication status	Published - 2010 Dec
Externally published	Yes

Keywords

Bi-2212
STM
Superconductor
Underdoped

ASJC Scopus subject areas

Electronic, Optical and Magnetic Materials
Condensed Matter Physics
Energy Engineering and Power Technology
Electrical and Electronic Engineering

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10.1016/j.physc.2009.11.065

Cite this

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title = "Control of carrier concentration in Bi-2212",

abstract = "We realized highly underdoped Bi-2212 crystals by using a Bi substitution into a Sr site (x), together with the excess oxygen (δ) control. The samples with x = 0-0.3 were grown by a traveling solvent floating zone method. For each x, δ was varied using the precision annealing method [1]. Under several assumptions, the effective Bi valence was evaluated to be +2.2, which is much lower than the formal valence +3. This indicates that the Bi substitution accompanies additional uptake in excess oxygen. The x dependent δ-doping level p relation and the observed shrink in the c-axis length are consistent with this assumption. Based on the decomposition phase diagram obtained in this study, Tc of 22 K was realized by careful annealing treatments. The samples showed a superconducting volume fraction of over 50%.",

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author = "S. Yamashita and T. Kasai and T. Fujii and T. Watanabe and A. Matsuda",

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TY - JOUR

T1 - Control of carrier concentration in Bi-2212

AU - Yamashita, S.

AU - Kasai, T.

AU - Fujii, T.

AU - Watanabe, T.

AU - Matsuda, A.

PY - 2010/12

Y1 - 2010/12

N2 - We realized highly underdoped Bi-2212 crystals by using a Bi substitution into a Sr site (x), together with the excess oxygen (δ) control. The samples with x = 0-0.3 were grown by a traveling solvent floating zone method. For each x, δ was varied using the precision annealing method [1]. Under several assumptions, the effective Bi valence was evaluated to be +2.2, which is much lower than the formal valence +3. This indicates that the Bi substitution accompanies additional uptake in excess oxygen. The x dependent δ-doping level p relation and the observed shrink in the c-axis length are consistent with this assumption. Based on the decomposition phase diagram obtained in this study, Tc of 22 K was realized by careful annealing treatments. The samples showed a superconducting volume fraction of over 50%.

AB - We realized highly underdoped Bi-2212 crystals by using a Bi substitution into a Sr site (x), together with the excess oxygen (δ) control. The samples with x = 0-0.3 were grown by a traveling solvent floating zone method. For each x, δ was varied using the precision annealing method [1]. Under several assumptions, the effective Bi valence was evaluated to be +2.2, which is much lower than the formal valence +3. This indicates that the Bi substitution accompanies additional uptake in excess oxygen. The x dependent δ-doping level p relation and the observed shrink in the c-axis length are consistent with this assumption. Based on the decomposition phase diagram obtained in this study, Tc of 22 K was realized by careful annealing treatments. The samples showed a superconducting volume fraction of over 50%.

KW - Bi-2212

KW - STM

KW - Superconductor

KW - Underdoped

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SP - S170-S172

JO - Physica C: Superconductivity and its applications

JF - Physica C: Superconductivity and its applications

IS - SUPPL.1

ER -

Control of carrier concentration in Bi-2212

Abstract

Keywords

ASJC Scopus subject areas

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