Pub Date : 2023-01-01DOI: 10.21883/ftt.2023.01.53916.474
Г.П. Потуданский, С. И. Курганский
Within the framework of the full-potential method of augmented plane waves with local orbitals, the electronic structure and X-ray spectral characteristics of the semiconductor and metal phases of iron disilicide were calculated. The total and partial densities of electronic states, the band structure, and X-ray absorption spectra of the iron K-edge were calculated. The results are compared with the known experimental data. An explanation is given of the change in the X-ray absorption near edge structure during the transition from the semiconductor phase to the metallic one.
{"title":"Электронная структура и рентгеноспектральные характеристики полупроводниковой и металлической фаз дисилицида железа","authors":"Г.П. Потуданский, С. И. Курганский","doi":"10.21883/ftt.2023.01.53916.474","DOIUrl":"https://doi.org/10.21883/ftt.2023.01.53916.474","url":null,"abstract":"Within the framework of the full-potential method of augmented plane waves with local orbitals, the electronic structure and X-ray spectral characteristics of the semiconductor and metal phases of iron disilicide were calculated. The total and partial densities of electronic states, the band structure, and X-ray absorption spectra of the iron K-edge were calculated. The results are compared with the known experimental data. An explanation is given of the change in the X-ray absorption near edge structure during the transition from the semiconductor phase to the metallic one.","PeriodicalId":24077,"journal":{"name":"Физика твердого тела","volume":"45 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88871506","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this work we studied the auto-oscillation mode of structures based on magnetic tunnel junctions. During the experiment we studied how different values and orientation of the magnetic field affect the efficiency of the self-generation regime for samples of various shapes. The auto-oscillation mode in samples was observed near the transition from one state of magnetization of the free layer to another. It was found that the maximum value of the power spectral density and its position relative to the frequency axis can be controlled by changing the magnitude and orientation of the external magnetic field.
{"title":"Влияние взаимного направления поляризатора и свободного слоя на автогенерацию магнитных туннельных переходов (МТП) разной геометрии","authors":"В.Р. Киктева, К.В. Киселева, Г.А. Кичин, П.Н. Скирдков, Константин Анатольевич Звездин","doi":"10.21883/ftt.2023.06.55646.03h","DOIUrl":"https://doi.org/10.21883/ftt.2023.06.55646.03h","url":null,"abstract":"In this work we studied the auto-oscillation mode of structures based on magnetic tunnel junctions. During the experiment we studied how different values and orientation of the magnetic field affect the efficiency of the self-generation regime for samples of various shapes. The auto-oscillation mode in samples was observed near the transition from one state of magnetization of the free layer to another. It was found that the maximum value of the power spectral density and its position relative to the frequency axis can be controlled by changing the magnitude and orientation of the external magnetic field.","PeriodicalId":24077,"journal":{"name":"Физика твердого тела","volume":"31 9 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78636749","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-01DOI: 10.21883/ftt.2023.06.55668.38
К. К. Маевский
An accurate description of the effect of extreme pressure and temperature on the physical properties of materials is required to understand the structure and composition of the mantle of the Earth and similar planets. One of such materials is enstatite MgSiO3, which causes increased interest in the investigating of its behavior under intense dynamic loads. It is proposed to consider the shock-wave loading of enstatite as a mixture of quartz oxides SiO2 and MgO periclase in an equal stoichiometric ratio based on experimental data in which decomposition of magnesium silicates was observed. Calculations are performed using a thermodynamically equilibrium model that takes into account the phase transitions of the components. Phase transitions of SiO2 and MgO are taken into account when modeling high-energy effects on enstatite. The results are compared with the data obtained on the basis of shock-wave loading experiments, as well as with calculations based on the PREM model performed based on the results of seismic exploration.
{"title":"Численное моделирование поведения энстатита до 1.4 TPa","authors":"К. К. Маевский","doi":"10.21883/ftt.2023.06.55668.38","DOIUrl":"https://doi.org/10.21883/ftt.2023.06.55668.38","url":null,"abstract":"An accurate description of the effect of extreme pressure and temperature on the physical properties of materials is required to understand the structure and composition of the mantle of the Earth and similar planets. One of such materials is enstatite MgSiO3, which causes increased interest in the investigating of its behavior under intense dynamic loads. It is proposed to consider the shock-wave loading of enstatite as a mixture of quartz oxides SiO2 and MgO periclase in an equal stoichiometric ratio based on experimental data in which decomposition of magnesium silicates was observed. Calculations are performed using a thermodynamically equilibrium model that takes into account the phase transitions of the components. Phase transitions of SiO2 and MgO are taken into account when modeling high-energy effects on enstatite. The results are compared with the data obtained on the basis of shock-wave loading experiments, as well as with calculations based on the PREM model performed based on the results of seismic exploration.","PeriodicalId":24077,"journal":{"name":"Физика твердого тела","volume":"19 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87320577","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-01DOI: 10.21883/ftt.2023.05.55502.37
В. В. Баковец, П. Е. Плюснин, И. В. Юшина, М. И. Рахманова, А. В. Сотников, И.П. Долговесова, Т.Д. Пивоварова
Samples of Gd2O3:Tb(3 mol%) phosphor were obtained by sol-gel method followed by annealing at 800oC and 1200oC in air. At high annealing temperature, the intensities of the main emission bands 484 and 541 nm increase, but the ratio of the intensities of these emission bands to their satellites 493 and 549 nm respectively decreases. Based on the analysis of X-ray diffractometry, radiation spectra, far-infrared and Raman spectroscopy, as well as diffuse reflectance spectroscopy, we established: the increase in the crystallinity of the samples with a significant reduction of the lattice strain stress at elevated annealing temperatures, changes in the structure of the bandgap with degenerated acceptor and donor zones of impurities Tb4+ and Tb3+ respectively. The diffuse reflection spectra of the sample after annealing at 800oC under optical excitation showed a direct charge transition through the bandgap with Eg = 2.56 eV. After elevated annealing temperature the concentration of Tb4+ ions decreases due to reduction to Tb3+. As a result, at low excitation energies the degeneracy of the acceptor zone is still preserved and there is a direct transition of charges through the bandgap with Eg = 2.55 eV. At high excitation energies the degeneracy of the acceptor zone is removed and there is a direct transition through the bandgap with Eg = 3.39 eV. These effects are accompanied by a relatively large increase in the emission intensity of the satellites, especially at the 549 nm.
{"title":"Особенности изменения интенсивностей основных полос фотолюминесценции ионов Tb-=SUP=-3+-=/SUP=- и их сателлитов в поликристаллическом люминофоре Gd-=SUB=-2-=/SUB=-O-=SUB=-3-=/SUB=-:Tb(3 mol%)","authors":"В. В. Баковец, П. Е. Плюснин, И. В. Юшина, М. И. Рахманова, А. В. Сотников, И.П. Долговесова, Т.Д. Пивоварова","doi":"10.21883/ftt.2023.05.55502.37","DOIUrl":"https://doi.org/10.21883/ftt.2023.05.55502.37","url":null,"abstract":"Samples of Gd2O3:Tb(3 mol%) phosphor were obtained by sol-gel method followed by annealing at 800oC and 1200oC in air. At high annealing temperature, the intensities of the main emission bands 484 and 541 nm increase, but the ratio of the intensities of these emission bands to their satellites 493 and 549 nm respectively decreases. Based on the analysis of X-ray diffractometry, radiation spectra, far-infrared and Raman spectroscopy, as well as diffuse reflectance spectroscopy, we established: the increase in the crystallinity of the samples with a significant reduction of the lattice strain stress at elevated annealing temperatures, changes in the structure of the bandgap with degenerated acceptor and donor zones of impurities Tb4+ and Tb3+ respectively. The diffuse reflection spectra of the sample after annealing at 800oC under optical excitation showed a direct charge transition through the bandgap with Eg = 2.56 eV. After elevated annealing temperature the concentration of Tb4+ ions decreases due to reduction to Tb3+. As a result, at low excitation energies the degeneracy of the acceptor zone is still preserved and there is a direct transition of charges through the bandgap with Eg = 2.55 eV. At high excitation energies the degeneracy of the acceptor zone is removed and there is a direct transition through the bandgap with Eg = 3.39 eV. These effects are accompanied by a relatively large increase in the emission intensity of the satellites, especially at the 549 nm.","PeriodicalId":24077,"journal":{"name":"Физика твердого тела","volume":"20 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83167315","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-01DOI: 10.21883/ftt.2023.04.55294.7
С.И. Гудков, А. В. Солнышкин, Р. Н. Жуков, Д. А. Киселев, Е. М. Семенова, А. Н. Белов
In this work, the electrophysical properties of metal-ferroelectric-semiconductor structures – Cu/LiNbO₃/Si and Ag/LiTaO₃/Si – with a ferroelectric layer thickness of 200 nm have been studied. The ferroelectric layers were deposited by RF‐magnetron sputtering. A topography study of thin film surface revealed a grain structure. The electrical conductivity mechanisms in Cu/LiNbO₃/Si and Ag/LiTaO₃/Si were considered. In a dependence of bias voltage value, there are a space charge-limited current, hopping conduction, and Schottky emission in Cu/LiNbO₃/Si structures. For Ag/LiTaO₃/Si structures, the space charge-limited current and hopping conduction were observed. An asymmetry of the current-voltage characteristics may indicate the presence of a potential barrier at the interface. For the studied structures, the value of the potential barrier was determined.
{"title":"Электропроводность и интерфейсные явления в тонкопленочных гетероструктурах на основе ниобата лития и танталата лития","authors":"С.И. Гудков, А. В. Солнышкин, Р. Н. Жуков, Д. А. Киселев, Е. М. Семенова, А. Н. Белов","doi":"10.21883/ftt.2023.04.55294.7","DOIUrl":"https://doi.org/10.21883/ftt.2023.04.55294.7","url":null,"abstract":"In this work, the electrophysical properties of metal-ferroelectric-semiconductor structures – Cu/LiNbO₃/Si and Ag/LiTaO₃/Si – with a ferroelectric layer thickness of 200 nm have been studied. The ferroelectric layers were deposited by RF‐magnetron sputtering. A topography study of thin film surface revealed a grain structure. The electrical conductivity mechanisms in Cu/LiNbO₃/Si and Ag/LiTaO₃/Si were considered. In a dependence of bias voltage value, there are a space charge-limited current, hopping conduction, and Schottky emission in Cu/LiNbO₃/Si structures. For Ag/LiTaO₃/Si structures, the space charge-limited current and hopping conduction were observed. An asymmetry of the current-voltage characteristics may indicate the presence of a potential barrier at the interface. For the studied structures, the value of the potential barrier was determined.","PeriodicalId":24077,"journal":{"name":"Физика твердого тела","volume":"39 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91371752","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-01DOI: 10.21883/ftt.2023.03.54741.538
О. В. Коплак, С.H. Кашин, Д. В. Королев, М. В. Жидков, В.П. Пискорский, Р. А. Валеев, Роман Борисович Моргунов
An analysis of the temperature and field dependences of the magnetization of Gd films and microwires was carried out, as well as an isothermal measurement of the magnetic part of the entropy at the Curie temperature. The magnetocaloric effect (MCE), measured as an isothermal increase in the magnetic part of the entropy, in microwires shows two peaks on the temperature dependence of the magnetic part of the entropy, in contrast to one peak in films. In films and microwires, the entropy maximum at 286–293 K, which corresponds to the Curie temperature, depends on the magnetic field, shifting in the same way in films and microwires with an increase in the field at the orientation of the MgO (111) substrate, which provides the maximum mechanical stresses in Gd. In microwires, the second maximum does not change the temperature of 320 K as the field increases to 9 T, but its amplitude increases linearly with the field. This maximum can be caused by a spin-reorientation transition.
{"title":"Магнитные свойства и магнитокалорический эффект в пленках и микропроводах Gd","authors":"О. В. Коплак, С.H. Кашин, Д. В. Королев, М. В. Жидков, В.П. Пискорский, Р. А. Валеев, Роман Борисович Моргунов","doi":"10.21883/ftt.2023.03.54741.538","DOIUrl":"https://doi.org/10.21883/ftt.2023.03.54741.538","url":null,"abstract":"An analysis of the temperature and field dependences of the magnetization of Gd films and microwires was carried out, as well as an isothermal measurement of the magnetic part of the entropy at the Curie temperature. The magnetocaloric effect (MCE), measured as an isothermal increase in the magnetic part of the entropy, in microwires shows two peaks on the temperature dependence of the magnetic part of the entropy, in contrast to one peak in films. In films and microwires, the entropy maximum at 286–293 K, which corresponds to the Curie temperature, depends on the magnetic field, shifting in the same way in films and microwires with an increase in the field at the orientation of the MgO (111) substrate, which provides the maximum mechanical stresses in Gd. In microwires, the second maximum does not change the temperature of 320 K as the field increases to 9 T, but its amplitude increases linearly with the field. This maximum can be caused by a spin-reorientation transition.","PeriodicalId":24077,"journal":{"name":"Физика твердого тела","volume":"8 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91256203","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-01DOI: 10.21883/ftt.2023.08.56152.76
А.А. Гермизина, Л. И. Наумова, М. А. Миляев, Р. С. Заворницын, А. И. Павлова, И. К. Максимова, В. В. Проглядо, И. Ю. Каменский, Владимир Васильевич Устинов
Rhombus-shaped microobjects formed by strips of two micrometers wide were fabricated from the spin valve film. The influence of the shape anisotropy on the layers magnetic moment rotation during the spin valve magnetic reversal is studied. A method for two-stage thermomagnetic treatment in a direction-fixed magnetic field has been found. The method allows to obtain the opposite sign values of the exchange bias fields in the non-parallel rhombus sides. The direction of the formed exchange bias is determined by the deviation of the strip from the uniaxial anisotropy axis and from the magnetic field applied during thermomagnetic treatment. Based on a rhombus-shaped microobject made from a single spin valve film, the device is a Full Wheatstone bridge. Each side of the rhombus is an active magnetically sensitive element.
{"title":"Формирование обменного смещения и анизотропия формы в микрообъектах на основе спиновых клапанов","authors":"А.А. Гермизина, Л. И. Наумова, М. А. Миляев, Р. С. Заворницын, А. И. Павлова, И. К. Максимова, В. В. Проглядо, И. Ю. Каменский, Владимир Васильевич Устинов","doi":"10.21883/ftt.2023.08.56152.76","DOIUrl":"https://doi.org/10.21883/ftt.2023.08.56152.76","url":null,"abstract":"Rhombus-shaped microobjects formed by strips of two micrometers wide were fabricated from the spin valve film. The influence of the shape anisotropy on the layers magnetic moment rotation during the spin valve magnetic reversal is studied. A method for two-stage thermomagnetic treatment in a direction-fixed magnetic field has been found. The method allows to obtain the opposite sign values of the exchange bias fields in the non-parallel rhombus sides. The direction of the formed exchange bias is determined by the deviation of the strip from the uniaxial anisotropy axis and from the magnetic field applied during thermomagnetic treatment. Based on a rhombus-shaped microobject made from a single spin valve film, the device is a Full Wheatstone bridge. Each side of the rhombus is an active magnetically sensitive element.","PeriodicalId":24077,"journal":{"name":"Физика твердого тела","volume":"17 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84843689","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-01DOI: 10.21883/ftt.2023.09.56249.72
Николай Иванович Сорокин, В. М. Каневский
A magnetoconductometric effect was found under pulsed magnetic action (B = 0.1–1 T) on a single crystal of the superionic conductor Pb0.67Cd0.33F2 (cubic symmetry, space group Fm¯3m, unit cell parameter a = 5.7575 A). The static electrical conductivity σdc was determined from impedance spectra in the frequency range (5–5)×105 Hz. In the absence of magnetic influence (B = 0) the ionic conductivity of a superionic crystal is σdc = 1.4×10–4 S/cm. When applying a magnetic field (B = (0.1−1) T) it increases, reaching σdc = 9.5 10−4 S/cm and σdc(B)/σdc(0) = 6.8 at B = 1 T. The nature of the magnetoconductometric effect in the superionic Pb0.67Cd0.33F2 is discussed in connection with the features its atomic structure.
{"title":"Воздействие слабого импульсного магнитного поля на ионную проводимость суперионного проводника Pb-=SUB=-0.67-=/SUB=-Cd-=SUB=-0.33-=/SUB=-F-=SUB=-2-=/SUB=-","authors":"Николай Иванович Сорокин, В. М. Каневский","doi":"10.21883/ftt.2023.09.56249.72","DOIUrl":"https://doi.org/10.21883/ftt.2023.09.56249.72","url":null,"abstract":"A magnetoconductometric effect was found under pulsed magnetic action (B = 0.1–1 T) on a single crystal of the superionic conductor Pb0.67Cd0.33F2 (cubic symmetry, space group Fm¯3m, unit cell parameter a = 5.7575 A). The static electrical conductivity σdc was determined from impedance spectra in the frequency range (5–5)×105 Hz. In the absence of magnetic influence (B = 0) the ionic conductivity of a superionic crystal is σdc = 1.4×10–4 S/cm. When applying a magnetic field (B = (0.1−1) T) it increases, reaching σdc = 9.5 10−4 S/cm and σdc(B)/σdc(0) = 6.8 at B = 1 T. The nature of the magnetoconductometric effect in the superionic Pb0.67Cd0.33F2 is discussed in connection with the features its atomic structure.","PeriodicalId":24077,"journal":{"name":"Физика твердого тела","volume":"93 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82448279","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-01DOI: 10.21883/ftt.2023.08.56165.127
А.С. Камзин, N. Dogan, O.M. Dogan, В. Г. Семенов
Functionalization (or coverage) MNF is a unique tool for creating particles with the properties required for biomedical applications. Therefore, the study of the magnetic properties of coated MNCs is the most important task of our time. The effect of changes in the concentration of Mn ions on the properties of MnxFe3-xO4 nanoparticles coated with oleic acid (OA) MnxFe3-xO4@OA (where x = 0, 0.25, 0.5, 0.75 and 1.0) to create stabilized magnetic fluids for various applications is investigated. The synthesis of MnxFe3-xO4@OA MNPs was carried out by thermal decomposition using manganese-oleate and iron oleate. The properties and phase states of the obtained MNPs were studied by X-ray diffraction (XRD) and Mossbauer spectroscopy. To understand the behavior of MNCs in small magnetic fields during hyperthermic treatment, Mossbauer studies of MnxFe3-xO4@OA particles were carried out when a magnetic field with a strength of 1.7 kOe was applied. It is established that the thermal decomposition method makes it possible to obtain single-phase superparamagnetic particles promising for biomedical applications
{"title":"Исследования магнитных наночастиц Mn-=SUB=-x-=/SUB=-Fe-=SUB=-3-x-=/SUB=-O-=SUB=-4-=/SUB=-@OA (0≤ x≤ 1.0) функционализированных олеиновой кислотой (ОА) для биомедицинских применений","authors":"А.С. Камзин, N. Dogan, O.M. Dogan, В. Г. Семенов","doi":"10.21883/ftt.2023.08.56165.127","DOIUrl":"https://doi.org/10.21883/ftt.2023.08.56165.127","url":null,"abstract":"Functionalization (or coverage) MNF is a unique tool for creating particles with the properties required for biomedical applications. Therefore, the study of the magnetic properties of coated MNCs is the most important task of our time. The effect of changes in the concentration of Mn ions on the properties of MnxFe3-xO4 nanoparticles coated with oleic acid (OA) MnxFe3-xO4@OA (where x = 0, 0.25, 0.5, 0.75 and 1.0) to create stabilized magnetic fluids for various applications is investigated. The synthesis of MnxFe3-xO4@OA MNPs was carried out by thermal decomposition using manganese-oleate and iron oleate. The properties and phase states of the obtained MNPs were studied by X-ray diffraction (XRD) and Mossbauer spectroscopy. To understand the behavior of MNCs in small magnetic fields during hyperthermic treatment, Mossbauer studies of MnxFe3-xO4@OA particles were carried out when a magnetic field with a strength of 1.7 kOe was applied. It is established that the thermal decomposition method makes it possible to obtain single-phase superparamagnetic particles promising for biomedical applications","PeriodicalId":24077,"journal":{"name":"Физика твердого тела","volume":"29 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81305356","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-01DOI: 10.21883/ftt.2023.06.55662.71
Николай Иванович Сорокин
The heterovalent solid solution Sr1−xYxF2+x with fluorite structure (sp. gr. Fm-3m) can be synthesized in single-crystal and nanoceramic forms. Comparison of their electrical properties shows that nanoceramics have a higher ionic conductivity than single crystals the same composition. In the single-crystal state of the solid solution, the migration mechanism dominates interstitial ions F' in the bulk of the sample, in the nanoceramic state ther is the vacancy migration mechanism V• along the grain boundaries of the sample. Using electrophysical and structural data, we calculated mobility μmob and concentration nmob of ionic charge carriers in a single crystal (a = 0.5722 nm) and ceramics (a = 0.57442 nm) of composition Sr0.7Y0.3F2.3. The defect mobility F′ (μmob = 4.5 10−10 cm2/(V s) at 500 K) in a single crystal is less than the mobility of vacancies V• in nanoceramics by 140 times. The concentration charge carriers is nmob = 1.1 1021 and 6.9 1021 cm-3 (2.2 and 14.2% of the total number of anions) for single crystal and nanoceramics, respectively.
{"title":"Подвижность носителей заряда в монокристалле и нанокерамике ионного проводника Sr-=SUB=-1-x-=/SUB=-Y-=SUB=-x-=/SUB=-F-=SUB=-2+x-=/SUB=- (x=0.3)","authors":"Николай Иванович Сорокин","doi":"10.21883/ftt.2023.06.55662.71","DOIUrl":"https://doi.org/10.21883/ftt.2023.06.55662.71","url":null,"abstract":"The heterovalent solid solution Sr1−xYxF2+x with fluorite structure (sp. gr. Fm-3m) can be synthesized in single-crystal and nanoceramic forms. Comparison of their electrical properties shows that nanoceramics have a higher ionic conductivity than single crystals the same composition. In the single-crystal state of the solid solution, the migration mechanism dominates interstitial ions F' in the bulk of the sample, in the nanoceramic state ther is the vacancy migration mechanism V• along the grain boundaries of the sample. Using electrophysical and structural data, we calculated mobility μmob and concentration nmob of ionic charge carriers in a single crystal (a = 0.5722 nm) and ceramics (a = 0.57442 nm) of composition Sr0.7Y0.3F2.3. The defect mobility F′ (μmob = 4.5 10−10 cm2/(V s) at 500 K) in a single crystal is less than the mobility of vacancies V• in nanoceramics by 140 times. The concentration charge carriers is nmob = 1.1 1021 and 6.9 1021 cm-3 (2.2 and 14.2% of the total number of anions) for single crystal and nanoceramics, respectively.","PeriodicalId":24077,"journal":{"name":"Физика твердого тела","volume":"35 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81574103","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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