TY - JOUR
T1 - Strong-coupling superconductivity in BaPd2As2 induced by soft phonons in the ThCr2Si2-type polymorph
AU - Kudo, Kazutaka
AU - Yamada, Yoshiaki
AU - Takeuchi, Takaaki
AU - Kimura, Takumi
AU - Ioka, Satoshi
AU - Matsuo, Genta
AU - Kitahama, Yutaka
AU - Nohara, Minoru
N1 - Funding Information:
The authors are grateful to M. Akoshima and H. Abe for helping to calibrate the instrument for specific-heat measurements, and to K. Fujimura, N. Nishimoto, T. Mizukami, and H. Ishii for their technical assistance in the experiments and data analyses for this work. A part of this work was performed at the Advanced Science Research Center, Okayama University. This work was partially supported by Grants-in-Aid for Scientific Research (Nos. 26287082, 15H01047, 15H05886, and 16K05451) provided by the Japan Society for the Promotion of Science (JSPS) and the Program for Advancing Strategic International Networks to Accelerate the Circulation of Talented Researchers from JSPS.
Publisher Copyright:
© 2017 The Physical Society of Japan.
PY - 2017/6/15
Y1 - 2017/6/15
N2 - The specific heat of two polymorphs of BaPd2As2 was measured. The ThCr2Si2-type polymorph (space group I4/mmm, D174h, No. 139) is a previously reported superconductor with a transition temperature Tc ≃ 3:5 K, while the CeMg2Si2-type polymorph (P4/mmm, D14h, No. 123) is a normal metal and does not exhibit superconductivity down to 1.8 K. Our results revealed that the ThCr2Si2-type has an anomalously low Debye temperature, indicative of soft phonons, compared to the CeMg2Si2-type. Moreover, a large specific-heat jump at Tc indicated that the superconductivity of ThCr2Si2-type is a strong-coupling type, which is likely derived from soft phonons.
AB - The specific heat of two polymorphs of BaPd2As2 was measured. The ThCr2Si2-type polymorph (space group I4/mmm, D174h, No. 139) is a previously reported superconductor with a transition temperature Tc ≃ 3:5 K, while the CeMg2Si2-type polymorph (P4/mmm, D14h, No. 123) is a normal metal and does not exhibit superconductivity down to 1.8 K. Our results revealed that the ThCr2Si2-type has an anomalously low Debye temperature, indicative of soft phonons, compared to the CeMg2Si2-type. Moreover, a large specific-heat jump at Tc indicated that the superconductivity of ThCr2Si2-type is a strong-coupling type, which is likely derived from soft phonons.
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U2 - 10.7566/JPSJ.86.063704
DO - 10.7566/JPSJ.86.063704
M3 - Article
AN - SCOPUS:85020697054
SN - 0031-9015
VL - 86
JO - Journal of the Physical Society of Japan
JF - Journal of the Physical Society of Japan
IS - 6
M1 - 063704
ER -