12 documents found, page 1 of 2
Modeling of the 2D-materials hybrid nanostructures based on ferroelectric polym...
Bystrov, V. S.; Paramonova, E. V.; Sapronova, A. V.; Shen, Hong; Meng, Xiangjian; Wang, Jianlu; Avakyan, L. A.Transition metal dichalcogenide MoS2 monolayers is very promising for many applications, especially in the fields of optics as emitters and detectors, in electronics as transistors. It is first of all due that they have a direct band gap Eg, which is dependent on external applied electric fields. To create such an electric field, it is proposed to use the field induced polarization of ferroelectric polymers suc...
Oxygen vacancies, the optical band gap (Eg) and photocatalysis ofhydroxyapatite...
Bystrov, V. S.; Piccirillo, C.; Tobaldi, D. M.; Castro, P. M. L.; Coutinho, J.; Kopyl, S.; Pullar, R.Hydroxyapatite (Ca10(PO4)6(OH)2, HAp) is a calcium phosphate employed both in biomedicine and forenvironmental remediation. It is known that HAp can also be photocatalytic under UV light, probablydue to oxygen deficiencies, but the mechanism is unclear, and reported optical band gap energies varygreatly. For the first time we propose the mechanisms and precise kinds of vacancies which may causethe photocatalyti...
Glycine nanostructures and domains in beta-glycine: computational modeling and ...
Bystrov, V. S.; Seyedhosseini, E.; Bdikin, I. K.; Kopyl, S.; Kholkin, A. L.; Vasilev, S. G.; Zelenovskiy, P. S.; Vasileva, D. S.; Shur, V. Ya.In this work computational molecular modeling of -glycine nanostructures is presented, using various approaches, mostly semi-empirical quantum approximation PM3 type in HyperChem software in restricted Hartree-Fock calculations. The main aims of present studies focus on the molecular modeling for the -glycine domains and domain walls formation and interaction. Obtained results are presented in visual 3D-models ...
Oxygen vacancies, the optical band gap (E-g) and photocatalysis of hydroxyapati...
Bystrov, V. S.; Piccirillo, C.; Tobaldi, D. M.; Castro, P. M. L.; Coutinho, J.; Kopyl, S.; Pullar, R. C.Hydroxyapatite (Ca-10(PO4)(6)(OH)(2), HAp) is a calcium phosphate employed both in biomedicine and for environmental remediation. It is known that HAp can also be photocatalytic under UV light, probably due to oxygen deficiencies, but the mechanism is unclear, and reported optical band gap energies vary greatly. For the first time we propose the mechanisms and precise kinds of vacancies which may cause the phot...
Modified Hydroxyapatite Structure and Properties: Modeling and Synchrotron Data...
Bystrova, A. V.; Dekhtyar, Yu. D.; Popov, A. I.; Coutinho, J.; Bystrov, V. S.First principle modeling and calculations of hydroxyapatite both native and surface modified and having various defects (OH vacancies, H inter-nodes) were performed. Local Density Approximation method used with calculations of Density of States allows us to analyze the experimental obtained work function data. Molecular modeling was confirmed by photo-electron measurements up to 6.5eV and photoluminescence expe...
Piezoelectricity in the Ordered Monoclinic Hydroxyapatite
Bystrov, V. S.The results are based on the first principle modeling and calculations of hydroxyapatite (HAP) nanostructures, especially, in ordered monoclinic phase. HAP structures were studied using local density approximation (LDA) method with calculations of density of states (DOS) in combination with molecular modeling by HyperChem. Computed data show that monoclinic and hexagonal phases can co-exist, especially in their...
Bioferroelectricity in Nanostructured Glycine and Thymine: Molecular Modeling a...
Bystrov, V. S.; Seyedhosseini, E.; Bdikin, I.; Kopyl, S.; Neumayer, S. M.; Coutinho, J.; Kholkin, A. L.Nanostructured aminoacid glycine and nucleobase thymine are very important for various biomedical applications. Experimentally, these structures demonstrate piezoelectric and polar properties. But the value of polarization and its switching behavior are not clear yet. In this work, computational modeling of glycine polymorphic phases (alpha and beta) and thymine nanostructures was performed using a combined met...
Computational study of hydroxyapatite structures, properties and defects
Bystrov, V. S.; Coutinho, J.; Bystrova, A. V.; Dekhtyar, Yu D.; Pullar, R. C.; Poronin, A.; Palcevskis, E.; Dindune, A.; Alkan, B.; Durucan, C.Hydroxyapatite (HAp) was studied from a first principle approach using the local density approximation (LDA) method in AIMPRO code, in combination with various quantum mechanical (QM) and molecular mechanical (MM) methods from HypemChem 7.5/8.0. The data obtained were used for studies of HAp structures, the physical properties of HAp (density of electronic states-DOS, bulk modulus etc) and defects in HAp. Compu...
Piezoelectricity and ferroelectricity in biomaterials: Molecular modeling and p...
Bystrov, V. S.; Seyedhosseini, E.; Kopyl, S.; Bdikin, I. K.; Kholkin, A. L.Piezoelectricity is one of the important functional properties inherent to many biomaterials. It stems from the non-centrosymmetric crystal structure of most biopolymers including proteins, polysaccharides, and lipids. Understanding the relationship between the generated electric field and applied mechanical stress has become the main motivation to studying piezoelectricity in biological systems and artificial ...
FMR study of carbon nanotubes filled with Fe3O4 nanoparticles
Kopyl, S.; Timopheev, A. A.; Bystrov, V. S.; Bdikin, I.; Teixeira, B. M. S.; Maevskij, E.; Sobolev, N. A.; Sousa, A. C. M.Ordered arrays of carbon nanotubes were produced using a non catalytic chemical vapour deposition. The multiwall nanotubes with an inner diameter of 120 nm were grown inside porous alumina templates and then filled with a magnetic colloid of 7.5 nm Fe3O4 particles. X-ray diffraction, electron microscopy and ferromagnetic resonance (FMR) were used to characterize structural and magnetic properties of the grown s...