Физика твердого тела最新文献

{"title":"О дираковской массе хаббардовских фермионов в сильно коррелированном топологическом сверхпроводнике высокого порядка","authors":"Сергей Владимирович Аксенов, А. Д. Федосеев, М. С. Шустин, А. О. Злотников","doi":"10.21883/ftt.2023.07.55830.31h","DOIUrl":"https://doi.org/10.21883/ftt.2023.07.55830.31h","url":null,"abstract":"Majorana corner modes have a number of advantages over the classical Majorana states in terms of performing topologically protected quantum computations. However, the problem of the influence of Coulomb repulsion on higher-order phases, which inevitably arises when trying to implement such systems in practice, has been poorly studied. In this article, we analyze the features of a topological invariant describing the nontrivial phase with the corner modes for a two-dimensional two-orbital model of a hybrid structure in the regime of extremely strong electron correlations. For this purpose, approximate wave functions of the edge states with a linear dispersion law and the associated Dirac masses, which arise when superconducting pairing in the system is taken into account, are obtained.","PeriodicalId":24077,"journal":{"name":"Физика твердого тела","volume":"36 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75006938","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}

{"title":"Неадиабатические переходы атомов и образование зародышей новой фазы в твердых телах","authors":"Ю. А. Хон","doi":"10.21883/ftt.2023.08.56142.100","DOIUrl":"https://doi.org/10.21883/ftt.2023.08.56142.100","url":null,"abstract":"A mechanism for the formation of nuclei of a new phase in a solid is proposed, determined by nonadiabatic Landau-Ziner transitions in an open system of nuclei and electrons. Based on the analysis of the equations of nonadiabatic molecular dynamics, two order parameters are identified. The dynamics of the nucleation and growth of the embryo is determined by two related nonlinear parabolic equations for order parameters. The conditions for the formation of stable and unstable embryos are found. It is shown that the formation of the embryo can proceed in an auto-oscillatory mode. The influence of the heating (cooling) rate on the formation of new phase nuclei is considered.","PeriodicalId":24077,"journal":{"name":"Физика твердого тела","volume":"303 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75430832","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}

{"title":"Особенности магнитных текстур в многослойных периодических структурах Co/Pt","authors":"Д.А. Татарский, Никита Сергеевич Гусев, О. Л. Ермолаева, Анна Николаевна Орлова, В. Л. Миронов, Сергей Анатольевич Гусев","doi":"10.21883/ftt.2023.07.55844.40h","DOIUrl":"https://doi.org/10.21883/ftt.2023.07.55844.40h","url":null,"abstract":"The results of systematic experimental studies of the magnetic state and crystal structure of multilayer films based on a ferromagnet/heavy metal pair (Co/Pt) by optical magnetometry, magnetic force microscopy, Lorentz and analytical transmission electron microscopy are presented. It is shown that with an increase in the number of Co/Pt periods in the films, an increase in the average size of crystal grains is observed, which leads to an increase in the dispersion of perpendicular anisotropy and, as a consequence, to a decrease in the size of magnetic domains and magnetization reversal fields. In addition, in films with n≥6 periods, the domain wall becomes hybrid; has an intermediate structure between the walls of the Neel and Bloch types.","PeriodicalId":24077,"journal":{"name":"Физика твердого тела","volume":"28 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77929619","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}

{"title":"Исследование магнитных наночастиц оксида железа, покрытых оксидом кремния, методом ферромагнитного резонанса","authors":"И. Г. Важенина, Сергей Викторович Столяр, А. В. Тюменцева, Михаил Н. Волочаев, Р. С. Исхаков, Сергей В. Комогорцев, В.Ф. Пьянков, Е. Д. Николаева","doi":"10.21883/ftt.2023.06.55644.01h","DOIUrl":"https://doi.org/10.21883/ftt.2023.06.55644.01h","url":null,"abstract":"Magnetic nanoparticles of magnetite with a size of ~8 nm synthesized with a different type of coating were studied by ferromagnetic resonance in the temperature range from 7 to 300 K. The features of the experimental temperature dependences of the parameters of the ferromagnetic resonance curve (the magnitude of the resonant field, line width and intensity) and their approximation allowed us to estimate the values of characteristic temperatures. Firstly, the value of the Vervey temperature and the dependence of its value on the type of coating were determined. Secondly, the temperature of transition of nanoparticles to the superparamagnetic state (blocking temperature) and the temperature range within which the magnetic structure of the outer shell of the magnetic nanoparticle is in the spin glass state are established","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":"75841162","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}

{"title":"Сегнетоэлектрические свойства тонких пленок цирконата-титаната свинца, полученных методом высокочастотного магнетронного распыления, в области морфотропной фазовой границы","authors":"М. В. Старицын, М. Л. Федосеев, Д. А. Киселев, Е.Ю. Каптелов, И. П. Пронин, С.В. Сенкевич, В. П. Пронин","doi":"10.21883/ftt.2023.02.54305.531","DOIUrl":"https://doi.org/10.21883/ftt.2023.02.54305.531","url":null,"abstract":"An experimental study of the crystal structure and ferroelectric properties of <110>-textured lead zirconate titanate films with a fine variation in their composition (with a change in the elemental ratio of zirconium and titanium atoms within 1.5%) near the morphotropic phase boundary revealed jump-like changes in the pseudocubic lattice parameter, dielectric permittivity and residual polarization. It is assumed that the observed anomalies correspond to a morphotropic transition from a rhombohedral to a mixture of tetragonal and monoclinic phases.","PeriodicalId":24077,"journal":{"name":"Физика твердого тела","volume":"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":"79307786","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}

{"title":"Влияние замещения ионами Bi-=SUP=-3+-=/SUP=- на структурно-фазовое состояние и особенности магнитной структуры твердого раствора BaFe-=SUB=-12-x-=/SUB=-Bi-=SUB=-x-=/SUB=-O-=SUB=-19-=/SUB=-","authors":"Алексей Валентинович Труханов, C.В. Труханов, В. В. Коровушкин, В. Г. Костишин, В. А. Турченко, Т. И. Зубарь, D. Sangaa, Н.В. Абметко, И.А. Греков, Д Б Мигас, Дарья Ивановна Тишкевич","doi":"10.21883/ftt.2023.08.56148.104","DOIUrl":"https://doi.org/10.21883/ftt.2023.08.56148.104","url":null,"abstract":"The results of studies of the features of the phase composition, crystal and magnetic structure of Bi-substituted barium hexaferrite BaFe12-xBixO19 (0.1≤ x≤ 1.2) by methods of Mossbauer spectroscopy, X-ray phase analysis, as well as image analysis by scanning electron microscopy are presented. Samples of Bi-substituted hexaferrites - BaFe12-xBixO19 (where x=0.1; 0.3; 0.6; 0.9 and 1.2) were synthesized by the method of solid-phase reactions with double annealing (at T=1100oC for 6 h) and intermediate grinding (for 0.5 h). The X-ray phase analysis allowed us to establish the limit of substitution of Fe3+ ions by Bi3+ ions. It has been shown that at a low level of substitution (x≤0.3) there are no impurity phases detected and the samples are characterized by a single-phase state with the spatial group P63/mmc. When the degree of substitution increases (x>0.3) the formation of impurity phases is noted, which can be explained by the difficulties of ion diffusion in the process of solid-phase synthesis, as well as the formation of defects in the structure of magentoplumbite due to the large ionic radius of Bi3+. As impurity phases in the studied compositions (x>0.3) Marked: BiFeO3 (Pr. Gr. Pnma); BiO2 (Pr. Gr. Fm-3m); BaBi2O6 (Pr. Gr. R-3) and BaO0,5Bi1,5O2,16 (Pr. Gr. Im-3m). The content of the main phase (Pr. Gr. P63mmc) at the same time decreases from 95.11 to 88.27 vol.% when increasing x from 0.6 to 1.2, respectively. The analysis performed by the method of Messbaurov spectroscopy showed that all Fe ions have a charge of 3+. And all parameters lie within the values characteristic of Fe3+ ions corresponding to the coordination of polyhedra: 12k. 4f2, 2a - octahedra, 4f1 - tetrahedron, and 2b - bipyramide. It is possible to single out a small monotonous decrease only for the 12k position. The analysis of SEM images showed an increase in the average particle size up to 10 mkm, depending on the concentration of bismuth oxide during the synthesis of hexaferrite.","PeriodicalId":24077,"journal":{"name":"Физика твердого тела","volume":"47 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84761550","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}

{"title":"Предельные параметры СИС-переходов в теории и технологические возможности их достижения","authors":"Михаил Александрович Тарасов, А.А. Ломов, А. М. Чекушкин, А. А. Гунбина, М. Ю. Фоминский, C.В. Краевский, Р. К. Козулин, А.В. Шадрин","doi":"10.21883/ftt.2023.07.55835.29h","DOIUrl":"https://doi.org/10.21883/ftt.2023.07.55835.29h","url":null,"abstract":"Tunneling Josephson junctions of the superconductor-insulator-superconductor (SIS) type have a history of more than 50 years, and theoretical estimates of the ultimate parameters of devices for receiving and processing signals based on them look very promising. In practice, in many cases, the actually achieved parameters turn out to be much worse than the theoretical ones, so for niobium SQUIDs the characteristic voltage Vc=IcRn at best reaches 200 µV, and according to theory it should be up to 2 mV. For Terahertz SIS mixers and oscillators, the main problems are a large specific capacitance, hysteresis, and leakage currents. These problems may be related to the morphology and crystal structure of superconductor films. In practice, films are granular, tunnel barriers are nonuniform, the effective area is about 10% of geometric area, leakage currents, parasitic capacitances occur. The crystal structure determines fundamentally different properties of the same elements, for example, for carbon it is diamond, graphite, fullerenes, nanotubes. Important components of a promising superconducting technology are: the use of single-crystal substrates matched in lattice constant and orientation with the grown films, optimization of growth temperature conditions, controlled formation of an oxide or nitride tunnel barrier. One option is to use a Schottky barrier for the semiconductor interlayer instead of a dielectric or normal metal one. This review presents the results of studying films by X-ray diffraction diagnostics, atomic force microscopy, and electron microscopy, showing the main bottlenecks of the existing technology with the deposition of niobium, niobium nitride, and aluminum films on oxidized standard silicon substrates, as well as the results of quasi-epitaxial growth of films on single-crystal substrates at various temperature conditions. Reproducible manufacturing of high-quality tunnel junctions can be achieved by implementing atomically smooth surfaces of tunnel contacts, which will improve the signal and noise characteristics of superconducting devices for receiving and processing information.","PeriodicalId":24077,"journal":{"name":"Физика твердого тела","volume":"31 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82052371","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}

{"title":"Термодинамическое поведение двумерной часовой модели с числом состояний спина q=5","authors":"А. К. Муртазаев, М.К. Бадиев, Магомед Абдулхаликович Магомедов, М. К. Рамазанов","doi":"10.21883/ftt.2023.08.56161.78","DOIUrl":"https://doi.org/10.21883/ftt.2023.08.56161.78","url":null,"abstract":"The Monte Carlo method was used to study the thermodynamic properties and phase transitions in a two-dimensional ferromagnetic clock model with q = 5 spin states on a triangular lattice. Systems with linear dimensions L × L = N, L = 24 ÷ 120 are considered. Two maxima are found on the temperature dependence of the heat capacity, which indicate the presence in the model under study of two phase transitions of the Berezinsky-Kosterlitz-Thouless type.","PeriodicalId":24077,"journal":{"name":"Физика твердого тела","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79829330","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}

{"title":"Влияние ориентации игольчатых включений NiSb на температурную зависимость сопротивления в монокристаллах Cd-=SUB=-0.95-=/SUB=-Ni-=SUB=-0.05-=/SUB=-Sb","authors":"В. С. Захвалинский, Е. А. Пилюк, А. В. Кочура, Л. А. Моргун, А. Б. Давыдов, Аунг Зо Хтет, В. В. Родионов, Б.А. Аронзон","doi":"10.21883/ftt.2023.03.54736.548","DOIUrl":"https://doi.org/10.21883/ftt.2023.03.54736.548","url":null,"abstract":"A composite Cd0.95Ni0.05Sb crystal consisting of CdSb and NiSb inclusions was obtained by the modified Bridgman method. It was shown by the methods of scanning electron microscopy, X-ray phase analysis, energy-dispersive X-ray spectroscopy, and studies of Raman spectra, that the main CdSb matrix was a block single crystal (orthorhombic Pbca structure) containing microcrystalline acicular inclusions of the second NiSb phase (hexagonal structure of the NiAs type P63/mmc). It has been found that the anisotropy of single-crystal NiSb needles in samples of the Cd0.95Ni0.05Sb crystalline composite (needles are directed along and across the current direction) significantly affects the resistance and magnetoresistance of the crystal. The interface is a needle-like inclusion - the matrix can become superconducting, which affects the conductivity of the composite as a whole. However, this superconductivity is insufficient for the transition at the experimental temperatures to the superconducting phase with zero resistance of the composite.","PeriodicalId":24077,"journal":{"name":"Физика твердого тела","volume":"54 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75796839","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}

{"title":"Транспортные свойства слоистых гетероструктур на базе проводящего полимера","authors":"К. Арутюнов, К. А. Беляев, В. В. Артемов, Алексей Леонидович Васильев, А. Р. Юсупов, Д. Д. Карамов, А. Н. Лачинов","doi":"10.21883/ftt.2023.01.53938.490","DOIUrl":"https://doi.org/10.21883/ftt.2023.01.53938.490","url":null,"abstract":"Polydiphenylenephthalide (PDP) belongs to the class of organic dielectrics, which exhibit electric conductive properties when an external electrostatic field and/or mechanical stress are applied. In this work, the transport properties of thin-film layered lead–PDP–lead structures were experimental-ly studied in a wide temperature range. At sufficiently high temperatures, the volt–ampere depend-ences are satisfactorily described in terms of the injection model of currents limited by the space charge. At temperatures below ~7.5 K, a number of samples exhibit features that can be explained by the effect of induced superconductivity in a thin film of a conducting polymer enclosed between two massive superconductors (lead).","PeriodicalId":24077,"journal":{"name":"Физика твердого тела","volume":"42 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81526622","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}