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Article Citation - Scopus: 1Determining the Hydrogen Production Potential of Conmo6se8 Chevrel Phases(Institute of Physics, 2025) Gencer, A.; Surucu, O.; Sahin, M.; Ozel, F.; Surucu, G.In this study, the ConMo6Se8 (n = 1, 2, 3, and 4) Chevrel phases are investigated by using Density Functional Theory (DFT) to reveal their potential for photocatalytic hydrogen production. The stability conditions of these phases reveal that CoMo6Se8, Co2Mo6Se8, and Co3Mo6Se8 satisfy the thermodynamic and mechanic stability properties, while Co4Mo6Se8 does not satisfy any of these properties. Furthermore, the formation enthalpy of these phases shows that CoMo6Se8, Co2Mo6Se8, and Co3Mo6Se8 can be synthesized experimentally due to having negative formation enthalpy values. Furthermore, the thermal stabilities of the machine-learning (ML) force fields are investigated by ab-initio molecular dynamics (AIMD) calculations. The electronic properties of these phases are also investigated in detail, and it is found that Co3Mo6Se8 has a suitable band gap for photocatalytic water splitting. Concerning the investigation of the valence band and conduction band levels, it is shown that Co3Mo6Se8 has a conduction band minimum level suitable for producing hydrogen. This study is the first attempt to reveal the hydrogen production performance of the ConMo6Se8 (n = 1, 2, 3, and 4) Chevrel phases as far as the literature is concerned, paving the ground for future investigations in this field. © 2024 IOP Publishing Ltd. All rights, including for text and data mining, AI training, and similar technologies, are reserved.Article Citation - WoS: 8Citation - Scopus: 9Electronic, Optical and Thermodynamic Characteristics of Bi12sio20 Sillenite: First Principle Calculations(Elsevier Science Sa, 2021) Isik, M.; Surucu, G.; Gencer, A.; Gasanly, N. M.Bi12XO20 (X: Si, Ge, Ti) ternary semiconducting compounds are known as sillenites and take a remarkable attention thanks to their attractive photorefractive properties. The present paper reports electronic, optical and thermodynamic characteristics of Bi12SiO20 by means of density functional theory (DFT) calculations. The crystalline structure of the compound was revealed as cubic with lattice constant of 10.135 angstrom. XRD pattern obtained from DFT calculations were compared with experimental data and there is a good consistency between them. The electronic band structure and density of state plots were presented in detail. The band gap energy of the compound was determined from electronic band structure and spectra of optical constants. The spectral dependencies of real and imaginary components of dielectric function, refractive index, extinction coefficient, absorption coefficient and loss function were plotted in the 0-12 eV spectral range. The revealed structural, electronic and optical characteristics were discussed taking into account the previously reported theoretical and experimental studies on the Bi12SiO20 sillenite.Article Citation - WoS: 5Citation - Scopus: 4Pressure and Spin Effect on the Stability, Electronic and Mechanic Properties of Three Equiatomic Quaternary Heusler (fevhfz, Z = Al, Si, and Ge) Compounds(Elsevier, 2021) Surucu, G.; Gencer, A.; Surucu, O.; Usanmaz, D.; Candan, A.In this paper, three equiatomic quaternary Heusler compounds -FeVHfZ (Z = Al, Si, and Ge) - are investigated for their structural, magnetic, electronic, mechanic, and lattice dynamic properties under pressure effect. These compounds are optimized for under three structural types and three magnetic phases: beta is the most stable structure with ferromagnetic phase. The electronic properties reveal that FeVHfAl is a half-metal, and that FeVHfSi and FeVHfGe are spin gapless semiconductors. In addition to electronic band structure, possible hybridization and partial density of states are presented. Furthermore, the mechanical properties are studied, and the three-dimensional direction-dependent mechanical properties are visualized under varying pressure effects. Our results reveal the half-metal and spin gapless semiconductor nature of the ferromagnetic FeVHfZ com-pounds, making them promising materials for spintronics applications.Article Citation - WoS: 12Citation - Scopus: 12First Principles Study of Bi12geo20< Electronic, Optical and Thermodynamic Characterizations(Elsevier, 2021) Isik, M.; Işık, Mehmet; Surucu, G.; Gencer, A.; Gasanly, N. M.; Işık, Mehmet; Department of Electrical & Electronics Engineering; Department of Electrical & Electronics EngineeringBismuth germanium oxide (Bi12GeO20) is one of the attractive members of sillenite compounds having fascinating photorefractive characteristics. The electronic, optical and thermodynamic properties of Bi12GeO20 were investigated using density functional theory (DFT) calculations. The experimental and calculated X-ray diffraction patterns were obtained as well-consistent with each other. The lattice constant of the cubic crystalline structure of Bi12GeO20 compound was calculated as 10.304 angstrom. The electronic band structure and partial density of states plots were reported and contribution of constituent atoms (Bi12GeO20) to the valence and conduction bands was presented. The band gap energy of the Bi12GeO20 was calculated as 3.20 eV. This wide direct band gap energy provides Bi12GeO20 significant potential in ultraviolet applications. The spectra of real and imaginary components of dielectric function, refractive index, extinction coefficient and absorption coefficient were drawn in the 0-10 eV energy range. Temperature-dependent heat capacity plot indicated the Dulong-Petit limit as 825 J/mol.K. The results of the present study would present worthwhile information to device application areas of Bi12GeO20 compound.
