scholarly journals Мартенситное превращение, магнитотранспортные свойства и магнитокалорический эффект в сплаве Ni-=SUB=-47-=/SUB=-Mn-=SUB=-42-=/SUB=-In-=SUB=-11-=/SUB=-

2019 ◽  
Vol 61 (4) ◽  
pp. 769
Author(s):  
Ю.В. Калетина ◽  
Е.Г. Герасимов ◽  
П.Б. Терентьев ◽  
А.Ю. Калетин
Keyword(s):  
Magnetic Field ◽  
Curie Temperature ◽  
Magnetocaloric Effect ◽  
Martensite Transformation ◽  
Room Temperature ◽  
Ferromagnetic Alloy ◽  
Spontaneous Transformation ◽  
Clapeyron Equation ◽  
Maximum Change ◽  
The Magnetic Field

AbstractThe structure, electric properties, and magnetocaloric effect in Ni_47Mn_42In_11 ferromagnetic alloy in which the martensite transformation temperature is close to room temperature and nearly coincides with the austenite Curie temperature are studied. It is revealed that the spontaneous transformation of martensite to austenite is accompanied with the decrease by 45% in its resistivity. In the martensite transformation induced by a magnetic field, a negative magnetoresistance is observed; it reaches ≈15% in the magnetic field with a strength of 18 kOe. The temperature dependence of the maximum change in the entropy in the martensite transformation induced by the magnetic field was calculated by using the Clausius–Clapeyron equation. It is shown that the maximum values of the magnetoresistance and magnetocaloric effect are observed near the temperature of the spontaneous martensite transformation.

The Magnetocaloric Effect in Ni-Mn-X (X=Ga, in) Heusler Alloys and Manganites with Magnetic Transition close to Room Temperature

2010 ◽  
Vol 168-169 ◽  
pp. 165-168
Author(s):  
Vasiliy D. Buchelnikov ◽  
Mikhail Drobosyuk ◽  
E.A. Smyshlyaev ◽  
O.O. Pavlukhina ◽  
A.V. Andreevskikh ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetocaloric Effect ◽  
Room Temperature ◽  
Direct Method ◽  
Magnetic Transition ◽  
Heusler Alloys ◽  
Field Change ◽  
Adiabatic Temperature Change ◽  
Magnetic Field Change ◽  
The Magnetic Field

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.

scholarly journals Magnetic properties of cobalt microwires measured by piezoresistive cantilever magnetometry

2014 ◽  
Vol 1 (1) ◽  
Author(s):  
G. Tosolini ◽  
J. M. Michalik ◽  
R. Córdoba ◽  
J. M. de Teresa ◽  
F. Pérez-Murano ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Room Temperature ◽  
Signal To Noise Ratio ◽  
Static Deflection ◽  
Magnetic Structures ◽  
Dual Beam ◽  
Piezoresistive Cantilevers ◽  
Good Signal ◽  
The Magnetic Field

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.

Martensitic Transformation and Mechanical Properties of Fe-Doped Ni54Mn21Ga25 Alloys

2011 ◽  
Vol 687 ◽  
pp. 500-504
Author(s):  
S. X. Xue ◽  
S.S. Feng ◽  
P. Y. Cai ◽  
Q T Li ◽  
H. B. Wang
Keyword(s):  
Magnetic Field ◽  
Mechanical Properties ◽  
Magnetic Properties ◽  
Martensitic Transformation ◽  
Curie Temperature ◽  
Directional Solidification ◽  
Transformation Temperature ◽  
Room Temperature ◽  
Martensitic Transformation Temperature ◽  
Polycrystalline Alloys

Ni54Mn21-xFexGa25（x=0,1,3,5,7,9）polycrystalline alloys were prepared by the technique of directional solidification and the effect of substituting Fe for Mn on the martensitic transformation and mechanical properties of the alloys was analyzed. It was found that the Curie temperature increased with increasing substitution while the martensitic transformation temperature decreased. The Fe-doped Ni54Mn21Ga25 alloys exhibit excellent magnetic properties at room temperature; the typical Ni54Mn20Fe1Ga25 alloy shows a large magnetic-induced-strain of -1040 ppm at a magnetic field of 4000 Oe.

Magnetocaloric Effect in Ni-Mn-Ga and Ni-Co-Mn-In Heusler Alloys

2009 ◽  
Vol 1200 ◽  
Author(s):  
Vasiliy Buchelnikov ◽  
Sergey Taskaev ◽  
Mikhail Drobosyuk ◽  
Vladimir Sokolovskiy ◽  
Viktor Koledov ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetocaloric Effect ◽  
Curie Point ◽  
Direct Method ◽  
Heusler Alloys ◽  
Field Change ◽  
Adiabatic Temperature Change ◽  
Magnetic Field Change ◽  
A Direct Method ◽  
The Magnetic Field

AbstractThe positive magnetocaloric effect (MCE) in the vicinity of the Curie point in Ni2+xMn1-xGa (x=0.33, 0.36, 0.39) Heusler alloys and the negative and positive MCE near the metamagnetostructural (MMS) transition and the Curie point, respectively, in Ni45Co5Mn36.5In13.5 Heusler alloy has been measured by a direct method. For the magnetic field change ΔH = 2 T, the maximal adiabatic temperature change ΔTad at the Curie point in Ni2+xMn1-xGa alloys is larger than 0.6 K. For Ni45Co5Mn36.5In13.5 alloy, the maximal value of ΔTad = 1.68 K (for the same magnetic field change, ΔH = 2 T) is observed at the MMS phase transition temperature.

Viscomagnetic Heat Flux Experiments as a Test of Gas Kinetic Theory in the Burnett Regime

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
Keyword(s):  
Magnetic Field ◽  
Boundary Layer ◽  
Heat Flux ◽  
External Magnetic Field ◽  
Room Temperature ◽  
Flow Direction ◽  
Rectangular Channel ◽  
Gas Kinetic Theory ◽  
The Magnetic Field ◽  
Good Agreement

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.

scholarly journals Influence of Magnetic Field on Evaporation Rate and Surface Tension of Water

2018 ◽  
Vol 2 (4) ◽  
pp. 68 ◽  
Author(s):  
Emil Chibowski ◽  
Aleksandra Szcześ ◽  
Lucyna Hołysz
Keyword(s):  
Magnetic Field ◽  
Surface Tension ◽  
Hydrogen Bonds ◽  
Room Temperature ◽  
Evaporation Rate ◽  
Water Evaporation ◽  
Water Molecules ◽  
Surface Tension Data ◽  
Ring Magnet ◽  
The Magnetic Field

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.

Bulk Transition Elements Based Materials for Magnetic Cooling Application

2011 ◽  
Vol 170 ◽  
pp. 248-252 ◽  
Author(s):  
Mohamed Balli ◽  
Osmann Sari ◽  
L. Zamni ◽  
A. Robert ◽  
J. Forchelet ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Composite Material ◽  
Powder Metallurgy ◽  
Magnetocaloric Effect ◽  
Temperature Change ◽  
Room Temperature ◽  
Test Bench ◽  
Transition Elements ◽  
Magnetic Systems ◽  
Magnetic Cooling

In this paper we investigate the performances of two bulk magnetocaloric refrigerants based on La(Fe,Co)13-xSix and prepared by powder metallurgy. Both materials were developed especially for a magnetic cooling machine. We have determined the magnetocaloric effect in term of temperature change under magnetic field using a test-bench with practical running conditions. ΔT was measured under 2 T and close to room temperature range. The obtained results will be compared with those of some reference materials reported in the literature. In addition, a composite material based on La(Fe,Co)13-xSix is proposed for magnetic systems using Ericsson and AMR cycles for refrigeration close to room temperature.

scholarly journals Colossal Negative Magnetoresistance Effect in a La1.37Sr1.63Mn2O7 Single Crystal Grown by Laser-Diode-Heated Floating-Zone Technique

Crystals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 547
Author(s):  
Si Wu ◽  
Yinghao Zhu ◽  
Junchao Xia ◽  
Pengfei Zhou ◽  
Haiyong Ni ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Single Crystal ◽  
Laser Diode ◽  
Room Temperature ◽  
Floating Zone ◽  
Magnetoresistance Effect ◽  
X Ray ◽  
Mr Effect ◽  
Distinct Features ◽  
The Magnetic Field

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.

Magnetic and magnetoresistive properties of nanocomposites based on Co and SiO

2019 ◽  
Vol 33 (12) ◽  
pp. 1950113 ◽  
Author(s):  
I. M. Pazukha ◽  
Y. O. Shkurdoda ◽  
A. M. Chornous ◽  
L. V. Dekhtyaruk
Keyword(s):  
Magnetic Field ◽  
Thin Film ◽  
Magnetic Properties ◽  
Room Temperature ◽  
Annealing Process ◽  
Anisotropic Character ◽  
Co Concentration ◽  
Beam Method ◽  
The Magnetic Field ◽  
Film Nanocomposites

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.

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