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ZnSSe ( x = 0, 0.41, 0.51, 0.91, 1) ternary alloy thin films with variable structural, optical and vibrational properties were prepared by thermal evaporation of solvothermally synthesized ZnS-ZnSe nanocomposite powders. The deposited films were uniform and have zinc-blende structure with (111) orientation. Variation of lattice parameter with composition was slightly non-linear with a bowing parameter of 0.12 Å. Spin orbit (SO) splitting of the valence band was observed in binary ZnSe and ternary samples with large Se atomic concentration such as ZnSSe and ZnSSe. The SO splitting energy decreases as the Se atomic concentration in the alloy decreases. Two phonon modes (corresponding to ZnS and ZnSe bonds) behavior were observed in the Raman spectra of the ternary alloys. The observed phonon mode frequencies shifted with changes in Se atomic concentration in agreement with theroretical predictions. Gap mode vibration of Se in ZnS lattice was also observed at 221 cm in the ternary sample with small Se atomic concentration (ZnSSe), which also matches closely with theoretically calculated values. [ABSTRACT FROM AUTHOR]

We report the electronic and magnetic properties along with the Curie temperature ( T C ) of the inverse full Heusler alloy (HA) Fe 2 CoAl obtained by using the first-principles computational method. Our calculations suggests that Fe 2 CoAl is a magnetic metal when treated within PBE-GGA under the applied compressive pressures. However, the implementation of electron-electron (U) ( i.e. , GGA+U) with varying compressive pressure ( P ) drastically changes the profile of the electronic structure. The application of GGA+U along with pressure induces ferromagnetic half-metallicity with an integer value of total magnetic moment ∼4.0 μ B per unit cell. The integer value is in accordance with the Slater-Pauling's rule. Here, we demonstrate the variation of semiconducting gap in the spin down channel. The band gap increases from 0.0 eV to 0.72 eV when increasing the pressure from 0 to 30 GPa. Beyond 30 GPa, the electronic band gap decreases, and it is completely diminished at 60 GPa, exhibiting metallic behaviour. The analysis of the computed results shows that the treatment of electron-electron interactions within GGA+U and the application of compressive pressure in Fe 2 CoAl enables d-d orbital hybridization giving rise to a half-metal ferromagnet. The T C calculated from mean field approximation (MFA) decreases up to 30 GPa and then increases linearly up to 60 GPa., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)