2019/01/14 by P. K. Maheshwari, V. Raghavendra Reddy, Maheshwari, P. K. +5
Materials Science · Physics and Astronomy · #FOS: Physical sciences #Iron-based superconductors research #Magnetic and transport properties of perovskites and related materials #Materials Science (cond-mat.mtrl-sci) #Rare-earth and actinide compounds #Strongly Correlated Electrons (cond-mat.str-el) #Superconductivity (cond-mat.supr-con)
paper · pdf · doi:10.48550/arxiv.1901.04224
openalex publication_date 2019/01/14 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Here, we report self flux single crystal growth of FeTe1-xSex for x = 0 to 0.50 series via solid state reaction route,the resulted crystals as seen are shiny. X Ray diffraction performed on the surface of crystals elucidated the growth in 00l plane, i.e. orientation in c direction only. Scanning electron microscopy (SEM) images showed slab like morphology and EDX (Energy dispersive X ray analyzer) confirmed that the crystals are closed to their designed compositions. Rietveld analysis of the XRD patterns of crushed crystal powders showed that the cell parameters decrease with Se content increase. Coupled magnetic and structural phase transition temperature, seen as a step in resistivity for the lower Se concentration and it is not detected for higher x values. Superconductivity is observed by resistivity measurement for higher Se concentration with a maximum temperature of 14K at x = 0.50. Thermally Activated Flux Flow (TAFF) analysis based on high field transport measurements in superconducting region done for x = 0.20 crystal. Raman spectroscopy at room temperature of synthesized samples exhibits all the allowed phonon modes with slight shift to higher frequency with Se content. Mossbauer spectra of FeTe1-xSex crystals series were recorded at 300 and 5K. At 5K, the average hyperfine field decreases systematically with Se content increase from 10.6 to 6.1Tesla for x = 0.0 to x = 0.20 samples. This indicates a possibility of co-existing magnetism and superconductivity in x = 0.07 to 0.20 crystals. For x = 0.50 sample, no hyperfine field related to magnetic ordering is seen. Based on above results, detailed phase diagram of the FeTe1-xSex compounds is defined in the present study.