Chapter 2. Physical properties of the Ca10(PtnAs8)(Fe2As2)5 (n=3, 4) 9 2.1 Crystal Structure of the Ca10(PtnAs8)(Fe2As2)5 (n = 3, 4 ) 9 2.2 Electronic Structure of the Ca10(PtnAs8)(Fe2As2)5 (n = 3, 4) 10 2.3 Optical properties of iron-based superconductors 14 2.4 Phase diagram 21 References 26
Chapter 3. Experimental and theoretical methods 27 3.1. Single crystal growth 27 3.2. Bridgman method 28 3.3. Single crystal growth of Ca10(PtnAs8)(Fe2As2)5 (n = 3, 4) 29 3.4. Fourier-transform infrared spectroscopy 30 3.5. Optical constants 39 3.6 Kramers-Kronig Relation 43 3.7 Drude-Lorentz Model 44 3.8 Sum rules 49 3.9 Superconducting gap response in optical conductivity 51 References 53
Chapter 4. Results and Discussion 54 4.1. Optical properties of optimally doped single-crystal Ca8.5La1.5(Pt3As8)(Fe2As2)5 54 4.2. Temperature dependence of the superconducting energy gaps in Ca9.35La0.65(Pt3As8)(Fe2As2)5 single crystal 82 4.3. Evidence for a preformed Cooper pair model in the pseudogap spectra of a Ca10(Pt4As8)(Fe2As2)5 single crystal with a nodal superconducting gap 103