In search of chemical clues

Lowe-Ma, Charlotte K.; Vanderah, Terrell A.

doi:10.1016/0921-4534(92)90469-s

Cited by 48 publications

(19 citation statements)

References 75 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…There are subtle contractions in the bond distances of Cu2-O31[46][47][48][49]. In the BaSrRCu 3 O 6+x series, however, structural anomalies in the Pr-compound appear to be due to the 'long' c-axis which is a result of the expansion of the Cu1-O1 (2.132 Å) and Pr-O21 distances.…”

mentioning

confidence: 90%

See 1 more Smart Citation

Interactions of Ba2YCu3O6+x with SrTiO3 substrate

Wong‐Ng

Yang

Kaduk

et al. 2011

Physica C: Superconductivity

View full text Add to dashboard Cite

mentioning

confidence: 90%

“…by Lowe-Ma and Vanderah[46] that there are structural anomalies in the Pr-analog in Ba 2 RCu 3 O 6+x , including the smaller lanthanidepolyhedral volume in Ba 2 PrCu 3 O 6+x as compared to the volume in Ba 2 NdCu 3 O 6+x . There are subtle contractions in the bond distances of Cu2-O31[46][47][48][49].…”

mentioning

confidence: 95%

Interactions of Ba2YCu3O6+x with SrTiO3 substrate

Wong‐Ng

Yang

Kaduk

et al. 2011

Physica C: Superconductivity

View full text Add to dashboard Cite

“…18 Because of the likelihood of vacancies, as well as Al and Cu, occupying the Cu͑1͒ sites, it is not possible to determine the Al content from diffraction alone. The Cu͑1͒ occupancies given in Tables I and II are based on zero Al content and are lower than the values given by Lowe-Ma and Vanderah.…”

Section: Sample Characterizationmentioning

confidence: 99%

Magnetic ordering inPrBa2Cu3−y
Longmore
¹
,
Boothroyd
²
,
Changkang
³

et al. 1996
Phys. Rev. B

View full text Add to dashboard Cite

The magnetic ordering in single crystals of PrBa 2 Cu 3 O 6ϩx has been investigated by elastic neutron scattering over the full range of temperatures for reduced and oxygenated crystals. The crystals were grown in alumina crucibles and therefore contained dissolved aluminum on the Cu͑1͒ site. Both aluminum and oxygen contents were analyzed in detail in order to establish their effects on the magnetic ordering. Our crystals exhibited Pr ordering and the two types of antiferromagnetic Cu ordering frequently reported in related compounds, but our results differ in several respects from previous studies. We observed three-dimensional ͑3D͒ collinear ordering of the Pr moments in the oxygenated crystal, with a finite correlation length of ͑34Ϯ3͒ Å parallel to the c axis, but in contrast to earlier neutron scattering results, which tentatively placed the Pr moment as being parallel to the c axis, we find the moment to be aligned well away from the c axis, in agreement with recent 170 Yb 3ϩ Mössbauer spectroscopy results. Ridges of scattering indicative of 2D magnetic ordering were seen in both oxygenated and reduced crystals, though we believe different magnetic moments are responsible in each case. The Pr Néel temperatures were suppressed compared with those reported for nominally pure samples. We have observed a very small 3D-ordered moment on the Cu͑1͒ site in the second type of Cu antiferromagnetic ordering ͑in the reduced crystal͒, but an ordered Cu͑1͒ moment may not necessarily be a characteristic of this structure. Our results are discussed with reference to previous works, and in the light of the Al substitution.

show abstract

“…All observable reflections in the x-ray powder pattern were used to refine the orthorhombic unit cell using a least-squares method. 4 Compared with the single-crystal structural data reported for PrBa 2 Cu 3 O 6 and PrBa 2 Cu 3 O 6.9 , 5 the c parameter ͓11.712͑1͒ Å͔ and unit cell volume ͓178.33͑3͒ Å͔ indicate an oxygen content of 6.9.…”

mentioning

confidence: 96%

“…21 It is hard to reconcile Ba-site Pr with extensive XRD studies by Lowe-Ma and Vanderah which indicate that PBCO is strictly isostructural with the superconducting 123 structures, except for a slight shortening of the apical Cu-O bond. 5 However, the sensitivity of these techniques preclude ruling out small (Ͻ5%) amounts of Pr substitution on the Ba site. The site selectivity and local structure sensitivity afforded by the EXAFS technique allows us to conclude that Pr does not substitute for Ba in this compound in amounts greater than 1%.…”

mentioning

confidence: 99%

Extended x-ray absorption fine structure measurements of nonsuperconducting PrBa2Cu3O6.9: Evidence against Ba site Pr substitution

Harris

Fatemi

Browning

et al. 1998

Journal of Applied Physics

View full text Add to dashboard Cite

Extended x-ray absorption fine structure (EXAFS) measurements on nonsuperconducting PrBa2Cu3O6.9 are reported. Theoretical Pr LII EXAFS data, calculated for the case of Y-site and Ba-site occupation, were least-squares fit to the experimental Pr LII EXAFS. Results indicate that the Pr ions overwhelmingly occupy the Y sites. These results present a serious challenge to models which rely on Ba-site Pr substitution as an explanation for the lack of superconductivity in PrBa2Cu3O6.9.

show abstract

In search of chemical clues

Cited by 48 publications

References 75 publications

Interactions of Ba2YCu3O6+x with SrTiO3 substrate

Interactions of Ba2YCu3O6+x with SrTiO3 substrate

Magnetic ordering inPrBa2Cu3−y
Longmore
¹
,
Boothroyd
²
,
Changkang
³

et al. 1996
Phys. Rev. B

Extended x-ray absorption fine structure measurements of nonsuperconducting PrBa2Cu3O6.9: Evidence against Ba site Pr substitution

Contact Info

Product

Resources

About

In search of chemical clues

Cited by 48 publications

References 75 publications

Interactions of Ba2YCu3O6+x with SrTiO3 substrate

Interactions of Ba2YCu3O6+x with SrTiO3 substrate

Magnetic ordering inPrBa2Cu3−yLongmore1, Boothroyd2, Changkang3 et al. 1996Phys. Rev. B

Extended x-ray absorption fine structure measurements of nonsuperconducting PrBa2Cu3O6.9: Evidence against Ba site Pr substitution

Contact Info

Product

Resources

About

Magnetic ordering inPrBa2Cu3−y
Longmore
¹
,
Boothroyd
²
,
Changkang
³

et al. 1996
Phys. Rev. B