Magnetic, structural, and Raman characterization of<i>R</i><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mrow><mml:mi mathvariant="normal">Ba</mml:mi></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msub></mml:mrow></mml:math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mrow><mml:mi mathvariant="normal">Cu</mml:mi></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msub></mml:mrow></mml:mat

Bennahmias, M.; O'Brien, J.C.; Radousky, H. B.; Goodwin, T.J.; Klavins, P.; Link, J. M.; Smith, Craig W.; Shelton, R. N.

doi:10.1103/physrevb.46.11986

Cited by 34 publications

(3 citation statements)

References 20 publications

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“…However, the absence of the chains in RCSCNO structure renders the role of the chains as extrinsic to the mechanism behind the suppression of superconductivity and other anomalous properties of these Pr-based compounds. Finally, we point out that the existence of the proposed subclass of compounds is also supported, though less definitely, by the properties of the PrBa 2 Cu 2 NbO 8 , 30 The exact origin of the correlation between the suppression of superconductivity and anomalous Pr magnetism is unclear at this time. However, this correlation suggests either a shared underlying mechanism or that one phenomenon directly leads to the other.…”

mentioning

confidence: 88%

Pr and Cu magnetism in (Pr1.5Ce0.5)
Goodwin
¹
,
Shelton
²
,
Radousky
³

et al. 1997
Phys. Rev. B
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The magnetic properties of nonsuperconducting ͑Pr 1.5 Ce 0.5 ͒Sr 2 Cu 2 M O 10Ϫ␦ with M ϭNb, Ta are characterized with dc magnetization, specific-heat, and neutron-diffraction experiments. Data for ͑Pr 1.5 Ce 0.5 ͒Sr 2 Cu 2 NbO 10Ϫ␦ reveal complex Cu magnetism marked by antiferromagnetic order below 200 K, spin structure transitions at 130 and 57 K, both collinear and noncollinear antiferromagnetic spin structures, and weak ferromagnetic behavior below 130 K. The data also indicate an anomalous ordering of the Pr spins near 10 K, a large linear contribution to the low-temperature specific heat, and a Pr 4 f crystal-field ground state similar to that found in PrBa 2 Cu 3 O 7 . Furthermore, there is evidence that the weak ferromagnetic behavior couples to the Pr ordering near 10 K. Identical Pr magnetism and similar Cu magnetism are found in ͑Pr 1.5 Ce 0.5 ͒Sr 2 Cu 2 TaO 10Ϫ␦ , deoxygenated ͑Pr 1.5 Ce 0.5 ͒Sr 2 Cu 2 NbO 10Ϫ␦ , and deoxygenated ͑Pr 1.5 Ce 0.5 ͒Sr 2 Cu 2 TaO 10Ϫ␦ . These results indicate that superconductivity is suppressed in these compounds in the same phenomenological manner as in PrBa 2 Cu 3 O 7 . We interpret this as evidence that superconductivity is suppressed by the same mechanism in both structures and propose that a general correlation exists between anomalous Pr magnetism and a lack of superconductivity in these Pr-based high-T C cuprates. The significance of these results and analyses to understanding and modeling the suppression of superconductivity by Pr in high-T C cuprates is discussed.

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mentioning

confidence: 88%

Pr and Cu magnetism in (Pr1.5Ce0.5)
Goodwin
¹
,
Shelton
²
,
Radousky
³

et al. 1997
Phys. Rev. B
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“…39 Also displayed are the corresponding Madelung potentials ͑in V͒, calculated in a point-ion model, and some ionization potentials. 40 Tables III and IV. 46,47 ͒ With all oxygen being O Ϫ2 , we find a net standard charge per cell of zero. Hence R122M -8 should not superconduct because it has no hypocharged oxygen-and, in fact, it does not superconduct.…”

Section: A Prediction Of Which Materials Superconductmentioning

confidence: 99%

Predicted properties ofNd1.5Ce0.5Sr2
Blackstead
¹
,
Dow
²

1998
Phys. Rev. B
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The charge-reservoir oxygen model of superconductivity predicts a critical temperature of T c Ϸ30 K for R 1.5 Ce 0.5 Sr 2 Cu 2 M O 10 (R222M -10) ͑with RϭEu, Sm, and Nd, and M ϭTa and Nb͒, in agreement with the measured values Ϸ28 K. The model also successfully predicts RBa 2 Cu 2 M O 8 (R122M -8) to be an insulator. Other predictions for R222M -10 in need of testing are ͑i͒ it is a p-type superconductor; ͑ii͒ the superconductivity originates primarily in the Sr-O layers, not in the cuprate-planes; ͑iii͒ on cuprate-plane Cu sites, of order ϳ1% Ni should depress T c to zero, while about six times as much Zn will be required to destroy superconductivity; ͑iv͒ magnetic impurities on Cu sites and Sr sites, but not rare-earth sites, will break Cooper pairs; ͑v͒ Pr on Sr sites will suppress T c ; ͑vi͒ the failure of Pr 1.5 Ce 0.5 Sr 2 Cu 2 M O 10 to superconduct is due to the antistructure defect (Pr Sr ϩ3 ,Sr Pr ϩ2 ); ͑vii͒ T c is small because the primary superconducting condensate in the charge-reservoir Sr-O layers is only Ϸ2 Å from the cuprate-planes; and ͑viii͒ the superconductivity should disappear with heavy Ce doping (z→1) in R 2Ϫz Ce z Sr 2 Cu 2 M O 10 . The relationships of R222M -10 to R122M -8, RBa 2 Cu 3 O 7 , and R 2Ϫz Ce z CuO 4 are discussed. ͓S0163-1829͑98͒10517-9͔

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“…Additional peaks were observed ͑7-8 %͒ in the XRD pattern of the PrCeInSCO, and our attempts to get completely rid of them were unsuccessful. We could not replace in PrCeTaSCO the Ba for Sr, and the main phase obtained was PrBa 2 TaO 6 , 11 with CeO 2 and CuO as extra phases.…”

Section: Methodsmentioning

confidence: 98%

Magnetic properties: Mössbauer, x-ray absorption spectroscopy, and specific-heat studies ofPr1.5Ce0.5
Asaf
¹
,
Felner
²
,
Schmitt
³

et al. 1996
Phys. Rev. B
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We have investigated Pr 1.5 Ce 0.5 M Sr 2 Cu 2 O z ͑zϭ9 or 10͒ materials ͑M ϭTa, In, and NbϩGa͒ by complementary experimental techniques. All materials studied are not superconducting. Magnetic susceptibility studies for M ϭTa reveal one magnetic anomaly at 23 K and irreversibility phenomena at higher temperatures. The presence of 0.5% 57 Fe dramatically affects the positions of the anomalies, and Mössbauer spectroscopy studies ͑MS͒ reveal that the Cu͑2͒ sites are magnetically ordered below T N ͑Cu͒ϭ130 K. This low T N ͑Cu͒ obtained is discussed. No specific heat anomaly was observed at 23 K, suggesting that the Pr sublattice does not order magnetically, and the anomalies in the susceptibility originate from the Cu moments. No anomalies in the susceptibility curves are found for M ϭIn and NbϩGa compounds. However, MS indicate that for the mixed compound, the Cu sites are magnetically ordered at low temperatures. The magnetic behavior of M ϭTa is compared to similar systems with two anomalies for M ϭNb at 11 and 52 K, and three anomalies for M ϭGa at 12, 52, and 94 K. X-ray absorption spectroscopy ͑XAS͒ indicates that in all materials studied, the Pr has a mixed valence close to 3. The Pr valence does not change with temperature.

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Magnetic, structural, and Raman characterization ofRBa2Cu2

Cited by 34 publications

References 20 publications

Pr and Cu magnetism in (Pr1.5Ce0.5)
Goodwin
¹
,
Shelton
²
,
Radousky
³

et al. 1997
Phys. Rev. B
Self Cite

Pr and Cu magnetism in (Pr1.5Ce0.5)
Goodwin
¹
,
Shelton
²
,
Radousky
³

et al. 1997
Phys. Rev. B
Self Cite

Predicted properties ofNd1.5Ce0.5Sr2
Blackstead
¹
,
Dow
²

1998
Phys. Rev. B
16
1
2
0
View full text Add to dashboard Cite

Magnetic properties: Mössbauer, x-ray absorption spectroscopy, and specific-heat studies ofPr1.5Ce0.5
Asaf
¹
,
Felner
²
,
Schmitt
³

et al. 1996
Phys. Rev. B
3
0
6
0
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Magnetic, structural, and Raman characterization ofRBa2Cu2

Cited by 34 publications

References 20 publications

Pr and Cu magnetism in (Pr1.5Ce0.5)Goodwin1, Shelton2, Radousky3 et al. 1997Phys. Rev. BSelf Cite

Pr and Cu magnetism in (Pr1.5Ce0.5)Goodwin1, Shelton2, Radousky3 et al. 1997Phys. Rev. BSelf Cite

Predicted properties ofNd1.5Ce0.5Sr2Blackstead1, Dow2 1998Phys. Rev. B16120View full textAdd to dashboardCite

Magnetic properties: Mössbauer, x-ray absorption spectroscopy, and specific-heat studies ofPr1.5Ce0.5Asaf1, Felner2, Schmitt3 et al. 1996Phys. Rev. B3060View full textAdd to dashboardCite

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About

Pr and Cu magnetism in (Pr1.5Ce0.5)
Goodwin
¹
,
Shelton
²
,
Radousky
³

et al. 1997
Phys. Rev. B
Self Cite

Pr and Cu magnetism in (Pr1.5Ce0.5)
Goodwin
¹
,
Shelton
²
,
Radousky
³

et al. 1997
Phys. Rev. B
Self Cite

Predicted properties ofNd1.5Ce0.5Sr2
Blackstead
¹
,
Dow
²

1998
Phys. Rev. B
16
1
2
0
View full text Add to dashboard Cite

Magnetic properties: Mössbauer, x-ray absorption spectroscopy, and specific-heat studies ofPr1.5Ce0.5
Asaf
¹
,
Felner
²
,
Schmitt
³

et al. 1996
Phys. Rev. B
3
0
6
0
View full text Add to dashboard Cite