scholarly journals Renovation of Interest in the Magnetoelectric Effect in Nanoferroics

2018 ◽  
Vol 63 (11) ◽  
pp. 1006 ◽  
Author(s):  
M. D. Glinchuk ◽  
V. V. Khist
Keyword(s):  
Size Effects ◽  
Magnetoelectric Effect ◽  
Bulk Material ◽  
Bismuth Ferrite ◽  
Phenomenological Theory ◽  
Magnetoelectric Coupling ◽  
Theoretical Studies ◽  
Coupling Coefficients ◽  
Bulk Materials ◽  
Magnetoelectric Properties

Recent theoretical studies of the influence of the magnetoelectric effect on the physical properties of nanosized ferroics and multiferroics have been reviewed. Special attention is focused on the description of piezomagnetic, piezoelectric, and linear magnetoelectric effects near the ferroid surface in the framework of the Landau–Ginzburg–Devonshire phenomenological theory, where they are considered to be a result of the spontaneous surface-induced symmetry reduction. Therefore, nanosized particles and thin films can manifest pronounced piezomagnetic, piezoelectric, and magnetoelectric properties, which are absent for the corresponding bulk materials. In particular, the giant magnetoelectric effect induced in nanowires by the surface tension is possible. A considerable influence of size effects and external fields on the magnetoelectric coupling coefficients and the dielectric, magnetic, and magnetoelectric susceptibilities in nanoferroics is analyzed. Particular attention is paid to the influence of a misfit deformation on the magnetoelectric coupling in thin ferroic films and their phase diagrams, including the appearance of new phases absent in the bulk material. In the framework of the Landau–Ginzburg–Devonshire theory, the linear magnetoelectric and flexomagnetoelectric effects induced in nanoferroics by the flexomagnetic coupling are considered, and a significant influence of the flexomagnetic effect on the nanoferroic susceptibility is marked. The manifestations of size effects in the polarization and magnetoelectric properties of semiellipsoidal bismuth ferrite nanoparticles are discussed.

scholarly journals Symmetry Analysis of Magnetoelectric Effects in Perovskite-Based Multiferroics

Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 574
Author(s):  
Zukhra Gareeva ◽  
Anatoly Zvezdin ◽  
Konstantin Zvezdin ◽  
Xiangming Chen
Keyword(s):  
Magnetoelectric Effect ◽  
Dipole Moments ◽  
Bismuth Ferrite ◽  
Structural Phase ◽  
Symmetry Analysis ◽  
Structural Phase Transitions ◽  
Magnetoelectric Effects ◽  
Magnetoelectric Properties ◽  
Tetragonal Crystal ◽  
First Time

In this article, we performed symmetry analysis of perovskite-based multiferroics: bismuth ferrite (BiFeO3)-like, orthochromites (RCrO3), and Ruddlesden–Popper perovskites (Ca3Mn2O7-like), being the typical representatives of multiferroics of the trigonal, orthorhombic, and tetragonal crystal families, and we explored the effect of crystallographic distortions on magnetoelectric properties. We determined the principal order parameters for each of the considered structures and obtained their invariant combinations consistent with the particular symmetry. This approach allowed us to analyze the features of the magnetoelectric effect observed during structural phase transitions in BixR1−xFeO3 compounds and to show that the rare-earth sublattice has an impact on the linear magnetoelectric effect allowed by the symmetry of the new structure. It was shown that the magnetoelectric properties of orthochromites are attributed to the couplings between the magnetic and electric dipole moments arising near Cr3+ ions due to distortions linked with rotations and deformations of the CrO6 octahedra. For the first time, such a symmetry consideration was implemented in the analysis of the Ruddlesden–Popper structures, which demonstrates the possibility of realizing the magnetoelectric effect in the Ruddlesden–Popper phases containing magnetically active cations, and allows the estimation of the conditions required for its optimization.

scholarly journals Size effects of ferroelectric and magnetoelectric properties of semi-ellipsoidal bismuth ferrite nanoparticles

2017 ◽  
Vol 714 ◽  
pp. 303-310 ◽  
Author(s):  
Victoria V. Khist ◽  
Eugene A. Eliseev ◽  
Maya D. Glinchuk ◽  
Maxim V. Silibin ◽  
Dmitry V. Karpinsky ◽  
...  
Keyword(s):  
Size Effects ◽  
Bismuth Ferrite ◽  
Ferrite Nanoparticles ◽  
Magnetoelectric Properties

Influence of temperature and humidity on the angle of repose of wood bulk materials

2016 ◽  
Author(s):  
И.В. Бачериков ◽  
Б.М. Локштанов
Keyword(s):  
Field Experiments ◽  
Bulk Material ◽  
Average Particle Size ◽  
Operating Conditions ◽  
Angle Of Repose ◽  
Wood Dust ◽  
Average Particle ◽  
Bulk Materials ◽  
Technical Literature ◽  
The Impact

При проектировании открытых и закрытых хранилищ измельченных сыпучих материалов древесных материалов, таких как щепа и опилки, большое значение имеет угол естественного откоса (статический и динамический) этих материалов. В технической литературе приводятся противоречивые сведения о величине этих углов, что приводит к ошибкам при проектировании складов. В справочных данных не учитываются условия, в которых эксплуатируются емкости для хранения сыпучих материалов, свойства и состояние этих сыпучих материалов. В свою очередь, ошибки при проектировании приводят к проблемам (зависание, сводообразование, «затопление» и т. д.) и авариям при эксплуатации бункеров и силосов на производстве. В статье представлены сведения, посвященные влиянию влажности и температуры на угол естественного откоса сыпучих материалов. На основании лабораторных и натурных экспериментов, проведенных с помощью специально разработанных методик и установок, была скорректирована формула для определения углов естественного откоса (статического и динамического) для измельченных древесных материалов в зависимости от их фракционного и породного состава, влажности (абсолютной и относительной) и температуры. При помощи скорректированной формулы можно определить угол естественного откоса древесных сыпучих материалов со среднегеометрическим размером частицы от 0,5 мм до 15 мм (от древесной пыли до технологической щепы) в различных производственных условиях. Статья может быть полезна проектировщикам при расчете угла наклона граней выпускающей воронки бункеров и силосов предприятий лесной отрасли и целлюлозо-бумажной промышленности. In the design of open and closed storage warehouses chopped wood materials for bulk materials such as wood chips and sawdust, great importance has an angle of repose (static and dynamic) of these materials. In the technical literature are conflicting reports about the magnitude of these angles, which leads to errors in the design of warehouses. In the referencesdoes not take into account the conditions under which operated capacities for storage of bulk materials, and properties and condition of the bulk material. The design errors lead to problems (hanging, arching, «flooding», etc.) and accidents in the operation of hoppers and silos at the mills. The article provides information on the impact of humidity and temperature on the angle of repose of granular materials. On the basis of laboratory and field experiments, conducted with the help of specially developed techniques and facilities has been adjusted formula for determining the angle of repose (static and dynamic) for the shredded wood materials depending on their fractional and species composition, humidity (absolute and relative) and temperature. It is possible, by using the corrected formula, to determine the angle of repose of loose wood materials with average particle size of from 0.5 mm to 15 mm (wood dust to pulpchips) in various operating conditions. The article can be helpful to designers in the calculation of the angle of inclination of the funnel faces produces bunkers and silos forest industries and pulp and paper industry.

scholarly journals Vibrational Spectroscopy of Boron Nitride at High Temperatures and Pressures

1989 ◽  
Vol 162 ◽  
Author(s):  
Gregory Y. Exarhos ◽  
Nancy J. Hess
Keyword(s):  
Boron Nitride ◽  
Bulk Material ◽  
Hexagonal Phase ◽  
Bulk Materials ◽  
Lattice Thermal Expansion ◽  
Line Frequency ◽  
Nitride Coatings ◽  
Scattering Measurements ◽  
Sputter Deposited ◽  
Inherent Strain

ABSTRACTRaman scattering measurements are used to distinguish between amorphous and crystalline phases in sputter deposited boron nitride coatings and bulk materials. Changes in vibrational line frequency and linewidth can be attributed to differences in particle size or inherent strain which can be quantified from pressure-dependent measurements of the bulk material. The response of the Raman-allowed E2g modes (hexagonal phase) to temperature is described by a forced dampeg harmonic oscillator model from which the intra- and interplanar lattice thermal expansion can be estimated.

Enhanced magnetoelectric coupling and dielectric constant in flexible ternary composite electrospun fibers of PVDF-HFP loaded with nanoclay and NiFe2O4 nanoparticles

2020 ◽  
Vol 44 (26) ◽  
pp. 11356-11364
Author(s):  
Sobi K. Chacko ◽  
M. T. Rahul ◽  
B. Raneesh ◽  
Nandakumar Kalarikkal
Keyword(s):  
Dielectric Constant ◽  
Room Temperature ◽  
Composite Fiber ◽  
Magnetoelectric Coupling ◽  
Electrospun Fibers ◽  
Fiber Mats ◽  
Ternary Composite ◽  
Magnetoelectric Properties ◽  
Nife2o4 Nanoparticles

Magnetoelectric flexible composite fiber mats with superior room temperature magnetoelectric properties.

Structures and magnetic properties of Sm-Fe-N bulk magnets produced by the spark plasma sintering method

2007 ◽  
Vol 22 (11) ◽  
pp. 3130-3136 ◽  
Author(s):  
Tetsuji Saito
Keyword(s):  
Magnetic Properties ◽  
Spark Plasma Sintering ◽  
Bulk Material ◽  
Decomposition Temperature ◽  
High Coercivity ◽  
Bulk Materials ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Sintering Method ◽  
N Powder

Sm-Fe-N powders were successfully consolidated at 873 K and below by the spark plasma sintering (SPS) method. Although the decomposition temperature of the hard magnetic Sm2Fe17N3 phase has been reported to be 873 K, partial decomposition of the Sm2Fe17N3 phase was noted in the bulk materials obtained by sintering at below that temperature. The resultant bulk materials showed a coercivity of around 0.24 MAm−1, significantly lower than that of the original Sm-Fe-N powder. It was found that decomposition of the Sm2Fe17N3 phase in the SPS method was significantly lowered by the addition of a small amount of Zn powder to the Sm-Fe-N powder. The bulk material obtained by sintering a mixture of Sm-Fe-N and Zn powder (10%Zn) at 723 K exhibited high coercivity, comparable with that of the original Sm-Fe-N powder.

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