# Superconductivity in rubidium-substituted Ba${}_{1-{}x}$Rb${}_{x}$Ti${}_{2}$Sb${}_{2}$O - Zurich Open Repository and Archive

von Rohr, Fabian; Nesper, Reinhard; Schilling, Andreas (2014). Superconductivity in rubidium-substituted Ba${}_{1-{}x}$Rb${}_{x}$Ti${}_{2}$Sb${}_{2}$O. Physical Review B, 89(094505):online.

## Abstract

We report on the synthesis and the physical properties of Ba${}_{1-{}x}$Rb${}_{x}$Ti${}_{2}$Sb${}_{2}$O ($x$ $\le$ $0.4$) by x-ray diffraction, superconducting quantum interference device magnetometry, resistivity, and specific-heat measurements. Upon hole doping by substituting Ba with Rb, we find superconductivity with a maximum Tc=5.4 K. Simultaneously, the charge-density-wave transition temperature is strongly reduced from TCDW≈55 K in the parent compound BaTi2Sb2O and seems to be suppressed for x≥0.2. The bulk character of the superconducting state for the optimally doped sample (x=0.2) is confirmed by the occurrence of a well developed discontinuity in the specific heat at Tc, with ΔC/Tc≈22 mJ/mol K2, as well as a large Meissner-shielding fraction of ≈40%. The isotropically averaged lower and upper critical fields of the optimally doped sample (x=0.2) are estimated to μ0Hc,1(0)≈3.8 mT and μ0Hc,2(0)≈2.3 T, respectively, indicating that these compounds are strongly type-II superconductors.

## Abstract

We report on the synthesis and the physical properties of Ba${}_{1-{}x}$Rb${}_{x}$Ti${}_{2}$Sb${}_{2}$O ($x$ $\le$ $0.4$) by x-ray diffraction, superconducting quantum interference device magnetometry, resistivity, and specific-heat measurements. Upon hole doping by substituting Ba with Rb, we find superconductivity with a maximum Tc=5.4 K. Simultaneously, the charge-density-wave transition temperature is strongly reduced from TCDW≈55 K in the parent compound BaTi2Sb2O and seems to be suppressed for x≥0.2. The bulk character of the superconducting state for the optimally doped sample (x=0.2) is confirmed by the occurrence of a well developed discontinuity in the specific heat at Tc, with ΔC/Tc≈22 mJ/mol K2, as well as a large Meissner-shielding fraction of ≈40%. The isotropically averaged lower and upper critical fields of the optimally doped sample (x=0.2) are estimated to μ0Hc,1(0)≈3.8 mT and μ0Hc,2(0)≈2.3 T, respectively, indicating that these compounds are strongly type-II superconductors.

## Citations

8 citations in Web of Science®
6 citations in Scopus®
Google Scholar™

## Downloads

43 downloads since deposited on 13 Feb 2015
35 downloads since 12 months
Detailed statistics

## Additional indexing

Item Type: Journal Article, refereed, original work 07 Faculty of Science > Physics Institute 530 Physics English 2014 13 Feb 2015 15:08 05 Apr 2016 18:57 American Physical Society 1098-0121 https://doi.org/10.1103/PhysRevB.89.094505

## Download

Preview
Filetype: PDF
Size: 1MB
View at publisher

## TrendTerms

TrendTerms displays relevant terms of the abstract of this publication and related documents on a map. The terms and their relations were extracted from ZORA using word statistics. Their timelines are taken from ZORA as well. The bubble size of a term is proportional to the number of documents where the term occurs. Red, orange, yellow and green colors are used for terms that occur in the current document; red indicates high interlinkedness of a term with other terms, orange, yellow and green decreasing interlinkedness. Blue is used for terms that have a relation with the terms in this document, but occur in other documents.
You can navigate and zoom the map. Mouse-hovering a term displays its timeline, clicking it yields the associated documents.