A calorimetric investigation of RbFeb>2 b>Asb>2 b> single crystals
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- 作者：Seunghyun Khim ; Saicharan Aswartham ; Vadim Grinenko ; Dmitry Efremov ; Christian G. F. Blum ; Frank Steckel ; Daniel Gruner ; Anja U. B. Wolter ; Stefan-Ludwig Drechsler ; Christian Heß ; Sabine Wurmehl and Bernd Bü ; chner
- 刊名：physica status solidi (b)
- 出版年：2017
- 出版时间：January 2017
- 年：2017
- 卷：254
- 期：1
- 全文大小：625K
- ISSN：1521-3951
文摘
We present properties of single crystals of the iron pnictide superconductor RbFeb>2 b>Asb>2 b> grown using a self-flux method. A bulk superconducting transition at on-construct="true" class="math-equation-construct">on-image="true" class="math-equation-image">on-mathml="true" class="math-equation-mathml" style="display:none">org/1998/Math/MathML">b xmlns:w="http://www.wiley.com/namespaces/wiley" xmlns:wiley="http://www.wiley.com/namespaces/wiley/wiley" xmlns:cr="urn://wiley-online-library/content/render" xmlns="http://www.w3.org/1998/Math/MathML">T c b> on-construct="true" class="math-equation-construct">on-image="true" class="math-equation-image">on-mathml="true" class="math-equation-mathml" style="display:none">org/1998/Math/MathML">o xmlns:w="http://www.wiley.com/namespaces/wiley" xmlns:wiley="http://www.wiley.com/namespaces/wiley/wiley" xmlns:cr="urn://wiley-online-library/content/render" xmlns="http://www.w3.org/1998/Math/MathML">∼ o> 2.6 K was consistently observed in resistivity, magnetic susceptibility, and specific heat measurements. 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In the superconducting state, we analyzed our specific heat data based on the s- and d-wave two-gap models. The presence of the small gap with 2on-construct="true" class="math-equation-construct">on-image="true" class="math-equation-image">on-mathml="true" class="math-equation-mathml" style="display:none">org/1998/Math/MathML">b xmlns:w="http://www.wiley.com/namespaces/wiley" xmlns:wiley="http://www.wiley.com/namespaces/wiley/wiley" xmlns:cr="urn://wiley-online-library/content/render" xmlns="http://www.w3.org/1998/Math/MathML">Δ 1 b>o xmlns:w="http://www.wiley.com/namespaces/wiley" xmlns:wiley="http://www.wiley.com/namespaces/wiley/wiley" xmlns:cr="urn://wiley-online-library/content/render" xmlns="http://www.w3.org/1998/Math/MathML" stretchy="false">( o>om/namespaces/wiley" xmlns:wiley="http://www.wiley.com/namespaces/wiley/wiley" xmlns:cr="urn://wiley-online-library/content/render" xmlns="http://www.w3.org/1998/Math/MathML">0 o xmlns:w="http://www.wiley.com/namespaces/wiley" xmlns:wiley="http://www.wiley.com/namespaces/wiley/wiley" xmlns:cr="urn://wiley-online-library/content/render" xmlns="http://www.w3.org/1998/Math/MathML" stretchy="false">) o> /on-construct="true" class="math-equation-construct">on-image="true" class="math-equation-image">on-mathml="true" class="math-equation-mathml" style="display:none">org/1998/Math/MathML">b xmlns:w="http://www.wiley.com/namespaces/wiley" xmlns:wiley="http://www.wiley.com/namespaces/wiley/wiley" xmlns:cr="urn://wiley-online-library/content/render" xmlns="http://www.w3.org/1998/Math/MathML">k B b>b xmlns:w="http://www.wiley.com/namespaces/wiley" xmlns:wiley="http://www.wiley.com/namespaces/wiley/wiley" xmlns:cr="urn://wiley-online-library/content/render" xmlns="http://www.w3.org/1998/Math/MathML">T c b>o xmlns:w="http://www.wiley.com/namespaces/wiley" xmlns:wiley="http://www.wiley.com/namespaces/wiley/wiley" xmlns:cr="urn://wiley-online-library/content/render" xmlns="http://www.w3.org/1998/Math/MathML">< o>om/namespaces/wiley" xmlns:wiley="http://www.wiley.com/namespaces/wiley/wiley" xmlns:cr="urn://wiley-online-library/content/render" xmlns="http://www.w3.org/1998/Math/MathML">1 was discussed to account for the large specific heat contribution remaining to low T far below on-construct="true" class="math-equation-construct">on-image="true" class="math-equation-image">on-mathml="true" class="math-equation-mathml" style="display:none">org/1998/Math/MathML">b xmlns:w="http://www.wiley.com/namespaces/wiley" xmlns:wiley="http://www.wiley.com/namespaces/wiley/wiley" xmlns:cr="urn://wiley-online-library/content/render" xmlns="http://www.w3.org/1998/Math/MathML">T c b> . The large on-construct="true" class="math-equation-construct">on-image="true" class="math-equation-image">on-mathml="true" class="math-equation-mathml" style="display:none">org/1998/Math/MathML">b xmlns:w="http://www.wiley.com/namespaces/wiley" xmlns:wiley="http://www.wiley.com/namespaces/wiley/wiley" xmlns:cr="urn://wiley-online-library/content/render" xmlns="http://www.w3.org/1998/Math/MathML">H ow>c 2 ow> b> anisotropy ratio, on-construct="true" class="math-equation-construct">on-image="true" class="math-equation-image">on-mathml="true" class="math-equation-mathml" style="display:none">org/1998/Math/MathML">b xmlns:w="http://www.wiley.com/namespaces/wiley" xmlns:wiley="http://www.wiley.com/namespaces/wiley/wiley" xmlns:cr="urn://wiley-online-library/content/render" xmlns="http://www.w3.org/1998/Math/MathML">Γ H b> = on-construct="true" class="math-equation-construct">on-image="true" class="math-equation-image">on-mathml="true" class="math-equation-mathml" style="display:none">org/1998/Math/MathML">bsup xmlns:w="http://www.wiley.com/namespaces/wiley" xmlns:wiley="http://www.wiley.com/namespaces/wiley/wiley" xmlns:cr="urn://wiley-online-library/content/render" xmlns="http://www.w3.org/1998/Math/MathML">H ow>c 2 ow>ab bsup> /on-construct="true" class="math-equation-construct">on-image="true" class="math-equation-image">on-mathml="true" class="math-equation-mathml" style="display:none">org/1998/Math/MathML">bsup xmlns:w="http://www.wiley.com/namespaces/wiley" xmlns:wiley="http://www.wiley.com/namespaces/wiley/wiley" xmlns:cr="urn://wiley-online-library/content/render" xmlns="http://www.w3.org/1998/Math/MathML">H ow>c 2 ow>c bsup> on-construct="true" class="math-equation-construct">on-image="true" class="math-equation-image">on-mathml="true" class="math-equation-mathml" style="display:none">org/1998/Math/MathML">o xmlns:w="http://www.wiley.com/namespaces/wiley" xmlns:wiley="http://www.wiley.com/namespaces/wiley/wiley" xmlns:cr="urn://wiley-online-library/content/render" xmlns="http://www.w3.org/1998/Math/MathML">∼ o> 7 near on-construct="true" class="math-equation-construct">on-image="true" class="math-equation-image">on-mathml="true" class="math-equation-mathml" style="display:none">org/1998/Math/MathML">b xmlns:w="http://www.wiley.com/namespaces/wiley" xmlns:wiley="http://www.wiley.com/namespaces/wiley/wiley" xmlns:cr="urn://wiley-online-library/content/render" xmlns="http://www.w3.org/1998/Math/MathML">T c b> indicates that the large gap would occupy a highly two-dimensional Fermi surface.