Raman scattering under pressure in ZnGa2Se4

Journal of Applied Physics

Pérez-González

et al. 2013

High-pressure Raman scattering measurements have been carried out in ZnGa 2 Se 4 for both tetragonal defect chalcopyrite and defect stannite structures. Experimental results have been compared with theoretical lattice dynamics ab initio calculations and confirm that both phases exhibit different Raman-active phonons with slightly different pressure dependence. A pressure-induced phase transition to a Raman-inactive phase occurs for both phases; however, the sample with defect chalcopyrite structure requires slightly higher pressures than the sample with defect stannite structure to fully transform into the Raman-inactive phase. On downstroke, the Raman-inactive phase transforms into a phase that could be attributed to a disordered zincblende structure for both original phases; however, the sample with original defect chalcopyrite structure compressed just above 20 GPa, where the transformation to the Raman-inactive phase is not completed, returns on downstroke mainly to its original structure but shows a new peak that does not correspond to the defect chalcopyrite phase. The pressure dependence of the Raman spectra with this new peak and those of the disordered zincblende phase is also reported and discussed. V C 2013 AIP Publishing LLC.

“…A similar HP Raman study was claimed to be conducted for DC-ZnGa 2 Se 4 samples in Ref. 22; however, we have recently commented in Ref. 28 that the samples studied in Ref.…”

Section: Introductionmentioning

confidence: 52%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

High-pressure Raman scattering study of defect chalcopyrite and defect stannite ZnGa2Se4

Journal of Applied Physics

Pérez-González

et al. 2013

“…In previous high-pressure Raman works, the disorder process at cation sites in OVCs with DC or DS structure was mainly suggested on the light of the extraordinary changes of the intensity and width of some Raman modes above certain pressures. 11,12,19,20,29 Indeed, cation disorder should affect drastically the intensities and widths of Raman modes because it is known that cation disorder in the DS structure results in broader Raman spectra with overlapped and less intense peaks than Raman spectra of the DC phase. 30 Therefore, to discuss the possible disorder processes occurring in DC-CdGa 2 Se 4 at cation sites, we have plotted the FWHM and the intensity of the most intense Raman modes in Figs.…”

Section: First Upstrokementioning

confidence: 99%

High-pressure optical and vibrational properties of CdGa2Se4: Order-disorder processes in adamantine compounds

Journal of Applied Physics

Manjón

et al. 2012

High pressure structural stability of BaLiF3 J. Appl. Phys. 110, 123505 (2011) Pressure effects on the transitions between disordered phases in supercooled liquid silicon J. Chem. Phys. 135, 204508 (2011) Microfabrication of controlled-geometry samples for the laser-heated diamond-anvil cell using focused ion beam technology Rev. Sci. Instrum. 82, 115106 (2011) First-principles investigations of elastic stability and electronic structure of cubic platinum carbide under pressure J. Appl. Phys. 110, 103507 (2011) Additional information on J. Appl. Phys. High-pressure optical absorption and Raman scattering measurements have been performed in defect chalcopyrite (DC) CdGa 2 Se 4 up to 22 GPa during two pressure cycles to investigate the pressure-induced order-disorder phase transitions taking place in this ordered-vacancy compound. Our measurements reveal that on decreasing pressure from 22 GPa, the sample does not revert to the initial phase but likely to a disordered zinc blende (DZ) structure the direct bandgap and Raman-active modes of which have been measured during a second upstroke. Our measurements have been complemented with electronic structure and lattice dynamical ab initio calculations. Lattice dynamical calculations have helped us to discuss and assign the symmetries of the Raman modes of the DC phase. Additionally, our electronic band structure calculations have helped us in discussing the order-disorder effects taking place above 6-8 GPa during the first upstroke.

Order–disorder processes in adamantine ternary ordered‐vacancy compounds

Manjón

Physica Status Solidi (b)

et al. 2013

Adamantine ternary ordered-vacancy compounds (OVCs) of the AB 2 X 4 family derive from the zincblende structure of binary AX compounds and share many properties with the chalcopyrite-type ternary ABX 2 compounds. AB 2 X 4 mainly crystallize in the defect chalcopyrite (or thiogallate) structure but also in other vacancy-ordered phases, like the defect stannite (DS, or defect famatinite) and the pseudocubic (PC) structures, where vacancies occupy a fixed Wyckoff site in an ordered and stoichiometric fashion. Order-disorder phase transitions have been studied in several adamantine OVCs at high temperatures and/or pressures, where OVCs undergo a phase transition to a disordered zincblende (DZ) structure on increasing temperature and to a disordered rocksalt (DR) structure on increasing pressure. It has been suggested that these order-disorder transitions should undergo via intermediate phases of partial disorder between the fully ordered phases and the fully disordered phases. In this work we study the different possible intermediate phases of partial disorder and discuss the possibility to find them with the help of vibrational spectroscopies, like Raman scattering or infrared measurements.