Study of Electronic Properties of 122 Iron Pnictide Through Structural, Carrier-Doping, and Impurity-Scattering Effects (eBook)

Tatsuya Kobayashi is an experimentalist in condensed-matter physics, and his work is concerned with strongly correlated electron systems and iron-based superconductors. Tatsuya Kobayashi received a Bachelor of Science, Master of Science, and Ph.D. from the Department of Physics, Graduate School of Science, Osaka University in 2011, 2013, and 2016, respectively. During his graduate program, he joined the group led by Professor Setsuko Tajima in the Department of Physics, Osaka University. Between April 2014 and March 2016, he was awarded a research fellowship for young scientists (DC2) by the Japan Society for the Promotion of Science (JSPS), and his research was supported by JSPS.

Supervisor’s Foreword 6
Parts of this thesis have been published in the following journal articlesT. Kobayashi, M. Nakajima, S. Miyasaka, and S. Tajima, Phys. Rev. B 94, 224516 (2016)T. Adachi, Y. Nakamatsu, T. Kobayashi, S. Miyasaka, S. Tajima, M. Ichimiya, M. Ashida, H. Sagayama, H. Nakao, R. Kumai, and Y. Murakami, J. Phys. Soc. Jpn. 85, 063705 (2016)J. Jandke, P. Wild, M. Schackert, S. Suga, T. Kobayashi, S. Miyasaka, S. Tajima, and W. Wulfhekel, Phys. Rev. B 93, 104528 (2016)E. Uykur, T. Kobayashi, W. Hirata, S. Miyasaka, S. Tajima, and C. A. Kuntscher, Phys. Rev. B 92, 245133 (2015)N. Murai, T. Fukuda, T. Kobayashi, M. Nakajima, H. Uchiyama, D. Ishikawa, S. Tsutsui, H. Nakamura, M. Machida, S. Miyasaka, S. Tajima, and A. Q. R. Baron, Phys. Rev. B 93, 020301(R) (2016) (Editors’ Suggestion)M. Miyamoto, H. Mukuda, T. Kobayashi, M. Yashima, Y. Kitaoka, S. Miyasaka, and S. Tajima, Phys. Rev. B 92, 125154 (2015)T. Kobayashi, K. Tanaka, S. Miyasaka, and S. Tajima, J. Phys. Soc. Jpn. 84, 094707 (2015)C. P. Strehlow, M. Ko?czykowski, J. A. Murphy, S. Teknowijoyo, K. Cho, M. A. Tanatar, T. Kobayashi, S. Miyasaka, S. Tajima, and R. Prozorov, Phys. Rev. B 90, 020508(R) (2014)H. Suzuki, T. Kobayashi, S. Miyasaka, T. Yoshida, K. Okazaki, L. C. C. Ambolode, II, S. Ideta, M. Yi, M. Hashimoto, D. H. Lu, Z.-X. Shen, K. Ono, H. Kumigashira, S. Tajima, and A. Fujimori, Phys. Rev. B 89, 184513 (2014)T. Kobayashi, S. Miyasaka, S. Tajima, and N. Chikumoto, J. Phys. Soc. Jpn. 83, 104702 (2014)S. Miyasaka, A. Takemori, T. Kobayashi, S. Suzuki, S. Saijo, S. Tajima, J. Phys. Soc. Jpn. 82, 124706 (2013)T. Kobayashi, S. Miyasaka, S. Tajima, T. Nakano, Y. Nozue, N. Chikumoto, H. Nakao, R. Kumai, and Y. Murakami, Phys. Rev. B 87, 174520 (2013)J. Murphy, C. P. Strehlow, K. Cho, M. A. Tanatar, N. Salovich, R. W. Giannetta, T. Kobayashi, S. Miyasaka, S. Tajima, and R. Prozorov, Phys. Rev. B 87, 140505(R) (2013)M. Ikeda, M. Hagiwara, T. Kobayashi, W. Hirata, S. Miyasaka, and S. Tajima, J. Korean Phys. Soc. 62, 2007 (2013)T. Kida, T. Kobayashi, S. Miyasaka, S. Tajima, and M. Hagiwara, J. Low Temp. Phys. 170, 346 (2013)S. Yeninas, M. A. Tanatar, C. Strehlow, J. Murphy, O. E. Ayala-Valenzucla, R. D. McDonald, U. Welp, W. K. Kwok, T. Kobayashi, S. Miyasaka, S. Tajima, and R. Prozorov, Phys. Rev. B, 87, 094503 (2013)T. Dulguun, H. Mukuda, T. Kobayashi, F. Engetsu, H. Kinouchi, M. Yashima, Y. Kitaoka, S. Miyasaka, and S. Tajima, Phys. Rev. B 85, 144515 (2012)T. Kobayashi, S. Miyasaka, and S. Tajima, J. Phys. Soc. Jpn. Suppl. B 81, SB045 (2012) 8
Acknowledgements 10
Contents 11
1 Introduction 13
1.1 Iron-Based Superconductor (FeSC) 13
1.2 Crystal Structure and Magnetic Order of FeSC 13
1.2.1 Electronic Structure 14
1.3 Phase Diagram of FeSC 15
1.4 Superconducting Property 18
1.4.1 Superconducting Gap Symmetry 18
1.4.2 Relationship Between Tc and Crystal Structure 18
1.4.3 Post-annealing Effect on Superconducting Properties 19
1.5 Normal State Property 19
1.5.1 Electronic Anisotropy 20
1.5.2 Optical Property 21
1.6 Aim of This Study 22
References 22
2 Experimental Methods 25
2.1 Single-Crystal Growth 25
2.1.1 SrFe2(As1-xPx)2 25
2.1.2 Ba(Fe1-xTMx)2As2 (TM=Cr, Mn, and Co) 26
2.1.3 Post Annealing Treatment 26
2.2 Transport Measurement 26
2.2.1 Resistivity Measurement 26
2.2.2 Hall Coefficient Measurement 26
2.2.3 Resistivity Measurement with Detwinned Crystal 27
2.3 Magnetization 28
2.4 X-Ray Diffraction Measurement 28
2.5 Specific Heat Measurement 28
2.6 Optical Measurement 28
References 29
3 Electronic Phase Diagram and Superconducting Property of SrFe2(As1-xPx)2 30
3.1 Introduction 30
3.2 Annealing Effect 31
3.3 Structural Analysis 32
3.4 Transport Measurement 35
3.5 Magnetic Susceptibility Measurement 40
3.6 Electronic Phase Diagram 41
3.7 Specific Heat in Superconducting State 42
3.8 Summary 46
References 46
4 In-Plane Resistivity Anisotropy of Ba(Fe1-xTMx)2As2 (TM = Cr, Mn, and Co) 48
4.1 Introduction 48
4.2 Resistivity Measurement with Detwinned Crystals 49
4.3 Hall Effect in Cr- and Mn-Ba122 53
4.4 Relation Between RH and ?? 54
4.5 Discussion on the Origin of the Resistivity Anisotropy 54
4.6 Summary 57
References 58
5 Optical Properties of Ba(Fe1-xTMx)2As2 (TM=Cr, Mn, and Co) 60
5.1 Introduction 60
5.2 Doping Dependence of Optical Spectra 61
5.3 Transition Metal Doping Effect on the AFO State 78
5.4 Magnetic/Nonmagnetic Impurity Effect 80
5.5 Localized Carrier Induced by Mn/Cr-Doping 86
5.6 Summary 88
References 89
6 Conclusion 91
6.1 Structural Properties and Superconductivity in P-Sr122 91
6.2 Resistivity Anisotropy in Ba(Fe1-xTMx)2As2 (TM=Cr, Mn, and Co) 92
6.3 Optical Conductivity in Ba(Fe1-xTMx)2As2 (TM=Cr, Mn, and Co) 93
6.4 Summary 94
6.5 Future Work 95
Appendix Curriculum Vitae 96