Electronic, transport, and magnetic properties of (Ca, Ba) _0.9 La _0.1 Fe _1.9 Pt _0.1 As ₂ compounds

Superconductivity and magnetic properties were studied for La and Pt substituted (Ca, Ba) _0.9 La _0.1 Fe _1.9 Pt _0.1 As ₂ samples using structural, resistivity and magnetic measurement techniques. All bulk samples were synthesized by solid-state reaction method and annealed under a specific annealing technique with a time-dependent annealing process in vacuumed quartz tubes. ThCr ₂ Si ₂ -type crystal structure was concluded for both samples varying with in- and out-of-plane lattice parameters. The superconducting critical temperatures were determined by resistivity and under H = 20 Oe magnetization measurements, which were performed between the temperature ranges of 0-200 K. The upper and lower critical fields were determined and possible Meissner effects were roughly figured out to understand the level of shielding from M-H measurements. The maximum critical temperature was obtained from Ca _0.9 La _0.1 Fe _1.9 Pt _0.1 As ₂ .