scholarly journals Магнитоэлектрические свойства мультиферроиков BiFeO-=SUB=-3-=/SUB=- замещенных цинком

2020 ◽  
Vol 62 (8) ◽  
pp. 1200
Author(s):  
Д.М. Юсупов ◽  
А.А. Амиров ◽  
И.И. Макоед ◽  
Y.A. Chaudhary ◽  
S.T. Bendre

The magnetoelectric properties of ceramic samples of multiferroics BiFe1-xZnxO3 and Bi1-xZnxFe1-xZnxO3 were studied in the magnetic field from 0 to 80 kOe at room temperature. All samples have linear dependences of the magnetoelectric coefficient αME with small hump-like maxima αME both at c 10 kHz and at 85 kHz. Magnetoelectric studies in samples of bismuth ferrite series with double substituted Zn show that double substitution of Bi3+ and Fe3+ ions by Zn2+ ions does not give the desired enhancement of magnetoelectric properties.

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Yuying Yang ◽  
Zhiyan Chen ◽  
Xiangqian Lu ◽  
Xiaotao Hao ◽  
Wei Qin

AbstractThe organic magnetoelectric complexes are beneficial for the development on flexible magnetoelectric devices in the future. In this work, we fabricated all organic multiferroic ferromagnetic/ferroelectric complexes to study magnetoelectric coupling at room temperature. Under the stimulus of external magnetic field, the localization of charge inside organic ferromagnets will be enhanced to affect spin–dipole interaction at organic multiferroic interfaces, where overall ferroelectric polarization is tuned to present an organic magnetoelectric coupling. Moreover, the magnetoelectric coupling of the organic ferromagnetic/ferroelectric complex is tightly dependent on incident light intensity. Decreasing light intensity, the dominated interfacial interaction will switch from spin–dipole to dipole–dipole interaction, which leads to the magnetoelectric coefficient changing from positive to negative in organic multiferroic magnetoelectric complexes.


2014 ◽  
Vol 1 (1) ◽  
Author(s):  
G. Tosolini ◽  
J. M. Michalik ◽  
R. Córdoba ◽  
J. M. de Teresa ◽  
F. Pérez-Murano ◽  
...  

AbstractWe present the magnetic characterization of cobalt wires grown by focused electron beam-induced deposition (FEBID) and studied using static piezoresistive cantilever magnetometry. We have used previously developed high force sensitive submicron-thick silicon piezoresistive cantilevers. High quality polycrystalline cobalt microwires have been grown by FEBID onto the free end of the cantilevers using dual beam equipment. In the presence of an external magnetic field, the magnetic cobalt wires become magnetized, which leads to the magnetic field dependent static deflection of the cantilevers. We show that the piezoresistive signal from the cantilevers, corresponding to a maximum force of about 1 nN, can be measured as a function of the applied magnetic field with a good signal to noise ratio at room temperature. The results highlight the flexibility of the FEBID technique for the growth of magnetic structures on specific substrates, in this case piezoresistive cantilevers.


1978 ◽  
Vol 33 (7) ◽  
pp. 749-760 ◽  
Author(s):  
G. E. J. Eggermont ◽  
P. W. Hermans ◽  
L. J. F. Hermans ◽  
H. F. P. Knaap ◽  
J. J. M. Beenakker

In a rarefied polyatomic gas streaming through a rectangular channel, an external magnetic field produces a heat flux perpendicular to the flow direction. Experiments on this “viscom agnetic heat flux” have been performed for CO, N2, CH4 and HD at room temperature, with different orientations of the magnetic field. Such measurements enable one to separate the boundary layer contribution from the purely bulk contribution by means of the theory recently developed by Vestner. Very good agreement is found between the experimentally determined bulk contribution and the theoretical Burnett value for CO, N2 and CH4 , yet the behavior of HD is found to be anomalous.


2018 ◽  
Vol 2 (4) ◽  
pp. 68 ◽  
Author(s):  
Emil Chibowski ◽  
Aleksandra Szcześ ◽  
Lucyna Hołysz

Using neodymium ring magnets (0.5–0.65 T), the experiments on the magnetic field (MF) effects on water evaporation rate and surface tension were performed at room temperature (22–24 °C). In accordance with the literature data, the enhanced evaporation rates were observed in the experiments conducted in a period of several days or weeks. However, the evaporated amounts of water (up to 440 mg over 150 min) in particular experiments differed. The evaporated amounts depended partially on which pole of the ring magnet was directed up. The relatively strong MF (0.65 T) caused a slight decrease in surface tension (−2.11 mN/m) which lasted longer than 60 min and the memory effect vanished slowly. The surface tension data reduced by the MF action are reported in the literature, although contrary results can be also found. The observed effects can be explained based on literature data of molecular simulations and the suggestion that MF affects the hydrogen bonds of intra- and inter-clusters of water molecules, possibly even causing breakage some of them. The Lorentz force influence is also considered. These mechanisms are discussed in the paper.


Crystals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 547
Author(s):  
Si Wu ◽  
Yinghao Zhu ◽  
Junchao Xia ◽  
Pengfei Zhou ◽  
Haiyong Ni ◽  
...  

We have grown La 1.37 Sr 1.63 Mn 2 O 7 single crystals with a laser-diode-heated floating-zone furnace and studied the crystallinity, structure, and magnetoresistance (MR) effect by in-house X-ray Laue diffraction, X-ray powder diffraction, and resistance measurements. The La 1.37 Sr 1.63 Mn 2 O 7 single crystal crystallizes into a tetragonal structure with space group I4/mmm at room temperature. At 0 T, the maximum resistance centers around ∼166.9 K. Below ∼35.8 K, it displays an insulating character with an increase in resistance upon cooling. An applied magnetic field of B = 7 T strongly suppresses the resistance indicative of a negative MR effect. The minimum MR value equals −91.23% at 7 T and 128.7 K. The magnetic-field-dependent resistance shows distinct features at 1.67, 140, and 322 K, from which we calculated the corresponding MR values. At 14 T and 140 K, the colossal negative MR value is down to −94.04(5)%. We schematically fit the MR values with different models for an ideal describing of the interesting features of the MR value versus B curves.


MRS Advances ◽  
2019 ◽  
Vol 4 (36) ◽  
pp. 1989-1999 ◽  
Author(s):  
Valery Sobol ◽  
Barys Korzun ◽  
Olga Mazurenko ◽  
Temirkhan Bizhigitov ◽  
Sabit Tomaev

ABSTRACTBismuth ferrite (BiFeO3) and La-, Nd- and Gd-substituted bismuth ferrite of the Bi1-xLaxFeO3, Bi1-xNdxFeO3, and Bi1-xGdxFeO3 types with the atomic part of the substitution element x equal up to 0.20 were synthesized by the solid-state reaction method using powders of oxides Bi2O3, Fe2O3, and La2O3, or Nd2O3, or Gd2O3 of pure grade quality and investigated using X-ray diffraction analysis. The magnetization was measured in the magnetic field up to 6.5⋅106 A/m at 5 and 300 K. It was found that the total substitution up to 0.20 atomic part of Bi by La, Nd, and Gd leads to the paramagnetic behavior of the doped bismuth ferrite at low temperatures in a wide range of magnetic field. Strong nonlinear dependence of magnetization on the magnetic field was detected and a ferromagnetic-like dependence of magnetization was observed for small magnetic fields. This can be explained by the exchange interaction between doping magnetic ions, as well as by the exchange interaction of these ions with ions of iron. The enhancement of magnetic properties with the increase of the content of the substitution is monotone and is more pronounced for the Bi1-xGdxFeO3 ceramics.


2019 ◽  
Vol 33 (12) ◽  
pp. 1950113 ◽  
Author(s):  
I. M. Pazukha ◽  
Y. O. Shkurdoda ◽  
A. M. Chornous ◽  
L. V. Dekhtyaruk

A series of thin-film nanocomposites based on ferromagnetic metal Co and insulator SiO were prepared using an electron-beam method. The magnetoresistive and magnetic properties of these structures deposited at room temperature and then annealed to 700 K were investigated. The results showed that at the Co concentration 40 [Formula: see text]x [Formula: see text] 60 at.%, thin-film nanocomposites exhibit magnetoresistance (MR) that is conditional on spin-dependent tunnelling of electrons. This range of concentrations corresponds to the prepercolation area according to the magnetic investigations. For samples with x [Formula: see text] 70 at.%, the anisotropic character of MR peculiar to the homogeneous ferromagnetic materials appears. According to the magnetic properties study, this range of concentrations corresponds to the area after transition through the percolation threshold. The annealing process in temperature range from 300 K to 700 K in the magnetic field slightly influenced the magnetoresistive properties of the thin-film nanocomposites based on Co and SiO for all range of concentrations.


2010 ◽  
Vol 168-169 ◽  
pp. 165-168
Author(s):  
Vasiliy D. Buchelnikov ◽  
Mikhail Drobosyuk ◽  
E.A. Smyshlyaev ◽  
O.O. Pavlukhina ◽  
A.V. Andreevskikh ◽  
...  

The magnetocaloric effect (MCE) in theNi2+xMn1-xGa (x = 0.33, 0.36, 0.39), Ni50Mn25In25, Ni54Mn21Ga18In7, Ni53.5Mn21.5Ga16In9, Ni45Co5Mn36.5In13.5 Heusler alloys and in the La0.7BayCa0.3-yMnO3 (y = 0.12, 0.24, 0.3) manganites at the Curie points have been measured by the direct method. For the magnetic field change H = 2 T, the maximal adiabatic temperature change Tad in the Ni2+xMn1-xGa alloys is larger than 0.6 K. For the Ni50Mn25In25 alloy the maximal value of Tad = 1.51 K (for the same magnetic field change H = 2 T) is observed at the magnetic phase transition temperature.


1957 ◽  
Vol 30 (2) ◽  
pp. 528-530
Author(s):  
Keichi Oshima ◽  
Hazime Kusumoto

Abstract Several authors have already reported their studies on natural rubber by the method of proton magnetic resonance. However, since there has been little work on the effect of elongation on proton magnetic resonance absorption, we present our investigation on the proton magnetic resonance absorption of stretched samples of vulcanized natural rubber. For this experiment a large permanent magnet shown in Figure 1 was constructed. The magnetic field strength was 6090 gauss at the center of the gap at 18° C. The magnet had a field inhomogeneity of about 0.01 gauss in a 0.2 cc. sample. The derivatives of the resonance line were recorded at fixed frequency, changing the magnetic field linearly in time with an automatic electronic bias control. Control of the temperature from liquid nitrogen to room temperature was performed by a cryostat similar to that described by Gutowsky.


2012 ◽  
Vol 77 ◽  
pp. 215-219
Author(s):  
Piotr Guzdek

Magnetoelectric effect in multiferroic materials is widely studied for its fundamental interest and practical applications. The magnetoelectric effect observed for single phase materials like Cr2O3, BiFeO3, Pb(Fe0.5Nb0.5)O3is usually small. A much larger effect can be obtained in composites consisting of magnetostrictive and piezoelectric phases. This paper investigates the magnetostrictive and magnetoelectric properties of nickel ferrite Ni0.3Zn0.62Cu0.08Fe2O4- relaxor Pb(Fe0.5Nb0.5)O3bulk composites. The magnetic properties of composites shows a dependence typical of such composite materials, i.e. it consists of a dominating signal from ferrimagnetic phase (ferrite) and a weak signal from paramagnetic (antiferromagnetic) phase (relaxors). Magnetoelectric effect at room temperature was investigated as a function of static magnetic field (300-7200 Oe) and frequency (10 Hz-10 kHz) of sinusoidal modulation magnetic field. The magnetoelectric effect increase slightly before reaching a maximum at HDC= 750 Oe and then decrease. The magnetoelectric coefficient increases continuously as frequency is raised, although this increase is less pronounced in the 1-10 kHz range.


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