scholarly journals Structure, Microstructure, and Magnetic Properties of Melt Spun Ni50Mn50−xInx Ribbons

2021 ◽  
Vol 7 (5) ◽  
pp. 63
Author(s):  
Karima Dadda ◽  
Safia Alleg ◽  
Joan Saurina ◽  
Lluïsa Escoda ◽  
Joan-Josep Suñol

Structural, microstructural, and magnetic properties of Heusler Ni50Mn50−xInx (x = 5 and 10) ribbons have been investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) coupled with energy dispersive X-ray spectroscopy (EDS), differential scanning calorimetry (DSC), and vibrating sample magnetometry (VSM). The as quenched Ni50Mn45In5 ribbons exhibit a mixture of monoclinic 14M (a = 4.329(3) Å, b = 5.530(3) Å, and c = 28.916(3) Å), and tetragonal L10 (a = b = 3.533(3) Å, and c = 7.522(3) Å) martensite structures, while Ni50Mn40In10 ribbons display a single monoclinic 14M phase (a = 4.262(3) Å, b = 5.692(3) Å, and c = 29.276(3) Å). After three heating/cooling cycles, in the temperature range of 303–873 K, the Rietveld refinement of the XRD patterns revealed the presence of a single 14M martensite for Ni50Mn45In5 ribbons, and a mixture of cubic L21 (31%) and 14M (69%) phases for Ni50Mn40In10 ribbons. The characteristic temperatures of the martensitic transition (Astart, Afinish, Mstart, and Mfinish), the thermal hysteresis temperature width, and the equilibrium temperature decreased with increasing indium content and heating cycles. The samples show a paramagnetic like behavior in the as quenched state, and a ferromagnetic like behavior after the third heating/cooling cycle.

2012 ◽  
Vol 535-537 ◽  
pp. 959-963
Author(s):  
Li Na Bai ◽  
Gui Xing Zheng ◽  
Jing Xin ◽  
Jian Jun Zhang

The influences of Gd concentration on martensitic transformation and magnetic properties of NiMnIn alloys were investigated by differential scanning calorimetry (DSC) , vibrating sample magnetometry (VSM), X-ray diffraction (XRD) and etc. It shows that addition of Gd enhances martensite transition temperature and that X-ray diffraction analysis of experimental alloys is revealed which the mixture is martensite and austenite at room temperature. These alloys show promise as a metamagnetic shape memory alloy with magnetic-field-induced shape memory effect.


2009 ◽  
Vol 635 ◽  
pp. 43-47 ◽  
Author(s):  
Sanjay Singh ◽  
S. Bhardwaj ◽  
A.K. Panda ◽  
V.K. Ahire ◽  
Amitava Mitra ◽  
...  

The martensitic transition and the ferro- to paramagnetic transition have been studied in a series of Ga excess Ni-Mn-Ga specimens [Ni2-xMnGa1+x (0.4≤ x≤ 0.9)] by differential scanning calorimetry and magnetization measurements. The martensitic transition exhibits a hysteresis whose width is similar to Ni2MnGa, indicating that the transition is thermoelastic. The latent heat of transformation is comparable with other Ni-Mn-Ga alloys. A substantial increase in the martensitic transition temperature is observed due to Ga doping. Interestingly, the x-ray diffraction pattern of all the compositions studied show a modulated martensitic structure in the martensitic phase.


2020 ◽  
Vol 10 (03) ◽  
pp. 2050003
Author(s):  
M. R. Hassan ◽  
M. T. Islam ◽  
M. N. I. Khan

In this research, influence of adding Li2CO3 (at 0%, 2%, 4%, 6%) on electrical and magnetic properties of [Formula: see text][Formula: see text]Fe2O4 (with 60% Ni and 40% Mg) ferrite has been studied. The samples are prepared by solid state reaction method and sintered at 1300∘C for 6[Formula: see text]h. X-ray diffraction (XRD) patterns show the samples belong to single-phase cubic structure without any impurity phase. The magnetic properties (saturation magnetization and coercivity) of the samples have been investigated by VSM and found that the higher concentration of Li2CO3 reduces the hysteresis loss. DC resistivity increases with Li2CO3 contents whereas it decreases initially and then becomes constant at lower value with temperature which indicates that the studied samples are semiconductor. The dielectric dispersion occurs at a low-frequency regime and the loss peaks are formed in a higher frequency regime, which are due to the presence of resonance between applied frequency and hopping frequency of charge carriers. Notably, the loss peaks are shifted to the lower frequency with Li2CO3 additions.


2010 ◽  
Vol 654-656 ◽  
pp. 1106-1109
Author(s):  
Ya Qiong He ◽  
Chang Hui Mao ◽  
Jian Yang

Nanocrystalline Fe-Co alloy powders, which were prepared by high-energy mechanical milling, were nitrided under the mixing gas of NH3/H2 in the temperature range from 380°C to 510°C. X-ray diffraction (XRD) was used to analyze the grain size and reaction during the processing. The magnetic properties of the nitrided powders were measured by Vibrating Sample Magnetometer (VSM). The results show that with the appearance of Fe4N phase after nitride treatment, and the grain-size of FeCo phase decreases with the increase of nitridation temperature between 380°C to 450°C.The saturation magnetization of nitrided alloy powder treated at 480°C is about 18% higher than that of the initial Fe-Co alloy powder, accompanied by the reduction of the coercivity. Transmission electron microscope (TEM) was used, attempting to further analyze the effect of Fe4N phase on microstructure and magnetic properties of the powder mixtures.


2012 ◽  
Vol 535-537 ◽  
pp. 950-953
Author(s):  
Li Na Bai ◽  
Gui Xing Zheng ◽  
Zhi Jian Duan ◽  
Jian Jun Zhang

The influences of Gd concentration on martensitic transformation and magnetic properties of NiMnIn alloys were investigated by differential scanning calorimetry (DSC) , vibrating sample magnetometry (VSM), X-ray diffraction (XRD) and etc. It is Observed through the experiment: the addition of Gd enhances martensite transition temperature;X-ray diffraction analysis of experimental alloys is revealed that to the mixture is martensite and austenite at room temperature; content of Gd is not proportional to the improvement of magnetic property.


2016 ◽  
Vol 31 (2) ◽  
pp. 104-109 ◽  
Author(s):  
Baozhuo Zhang ◽  
Marcus L. Young

Many technological applications of austenitic shape memory alloys (SMAs) involve cyclical mechanical loading and unloading in order to take advantage of pseudoelasticity. In this paper, we investigated the effect of mechanical bending of pseudoelastic NiTi SMA wires using high-energy synchrotron radiation X-ray diffraction (SR-XRD). Differential scanning calorimetry was performed to identify the phase transformation temperatures. Scanning electron microscopy images show that micro-cracks in compressive regions of the wire propagate with increasing bend angle, while tensile regions tend not to exhibit crack propagation. SR-XRD patterns were analyzed to study the phase transformation and investigate micromechanical properties. By observing the various diffraction peaks such as the austenite (200) and the martensite (${\bar 1}12$), (${\bar 1}03$), (${\bar 1}11$), and (101) planes, intensities and residual strain values exhibit strong anisotropy, depending upon whether the sample is in compression or tension during bending.


1991 ◽  
Vol 69 (2) ◽  
pp. 277-285 ◽  
Author(s):  
Jing-Long Du ◽  
Steven J. Rettig ◽  
Robert C. Thompson ◽  
James Trotter

The synthesis of the β and γ forms of M(Ph2PO2)2 where M = Co and Mn are described and the compounds are characterized by infrared spectroscopy, differential scanning calorimetry, X-ray powder diffraction, and low-temperature (2–80 K) magnetic susceptibility studies. Single crystal X-ray diffraction studies are reported on the γ forms. Crystals of the γ forms of poly-bis(μ-diphenylphosphinato)cobalt(II) and poly-bis(μ-diphenylphosphinato)manganese(II) are isomorphous, crystallizing with 4 formula units per unit-cell in the monoclinic space group P21/c. Lattice constants are a = 8.080(2), 8.161(1), b = 23.550(6), 23.751(1), c = 11.726(3), 11.6946(6) Ǻ, and β = 92.88(2), 93.026(8)° for the Co and Mn derivatives respectively. The structures were solved by heavy atom methods and were refined by full-matrix least-squares procedures to R = 0.039 and 0.045 for 4041 and 2878 reflections with I ≥ 3σ(I), respectively. Both crystal structures consist of double phosphinate-bridged chain polymers containing tetrahedrally coordinated metal atoms: Co—O = 1.950(2)–1.963(2) Ǻ, O—Co—O = 104.81(8)–117.77(9)°, Mn—O = 2.016(3)–2.033(3) Ǻ, O—Mn—O = 103.2(1)–114.7(1)°. All four compounds exhibit antiferromagnetic coupling and magnetic susceptibilities have been analyzed according to two Heisenberg models for linear chains of metal ions with S = 3/2 for cobalt and S = 5/2 for manganese. The Weng model (with values for the Wagner and Friedberg model in parentheses) gives –J = 0.25 (0.26) cm−1 and 0.55 (0.60) cm−1 for the β and γ forms, respectively, of Co(Ph2PO2)2, and 0.34 (0.36) cm−1 and 0.17 (0.17) cm−1 for the β and γ forms, respectively, of Mn(Ph2PO2)2. Key words: crystal structure, diphenylphosphinates of cobalt(II) and manganese(II), magnetic properties.


Author(s):  
Fatiha Djaidi ◽  
Hanane Mechri ◽  
Mohammed Azzaz

Abstract The Fe2CrSi nanostructured Heusler alloy was prepared by mechanical alloying followed by heat treatment. The structure, microstructure, and magnetic properties of the samples were studied by the following analysis methods: X-ray diffraction, scanning electron microscopy with energy dispersive X-ray spectrometry, transmission electron microscopy, and a vibrating sample magnetometer. The a-Fe (Si, Cr) solid solution with a disordered body centered cubic (bcc) crystal structure was obtained after 24 h of milling. An example of the sample milled for 32 h with a disordered crystal structure a-Fe(Si, Cr) was chosen to investigate the transformation with temperature using differential scanning calorimetry. The effect of annealing temperatures on the structural, microstructural, and magnetic properties of the ordered Fe2CrSi Heusler phase for the sample milled for 32 h was investigated.


2016 ◽  
Vol 849 ◽  
pp. 52-57 ◽  
Author(s):  
Jing Xu ◽  
Zheng Feng Zhao ◽  
Yan Wang

In this paper, the effects of annealing treatment on the microstructure, thermal property and magnetic properties of mechanical alloyed FeSiBAlNiC and FeSiBAlNiCe amorphous high entropy alloys has been systematically investigated using X-ray diffraction, differential scanning calorimetry, field emission scanning electron microscopy and alternation gradient magnetometry. The results showed that annealing at different temperature range induced the pronounced microstructural evolution from the amorphous phase to a mixture of amorphous phase and intermetallics but without any formation of solid solutions. In addition, the thermal stability and heat resistance were enhanced with increasing the annealing temperature. Similarly, annealing treatment also had significant effect on the particle morphology, making the particles evolve from near-round shape to plate-like shape. Furthermore, subsequent annealing of W6-Ce amorphous HEAs enhanced the saturation magnetization (Ms) remarkably (from 0.6 emu/g of 140 h as-milled W6-Ce to 20.17 emu/g). But for the Ms values of the 140 h as-milled amorphous W6-C HEAs, annealing in different temperature range all exhibited a slightly decreased effect.


2000 ◽  
Vol 55 (7) ◽  
pp. 567-575 ◽  
Author(s):  
K. Griesar ◽  
E. A. Soto-Bustamante ◽  
W. Haase

Abstract The syntheses of different nitroxide radicals are reported. The thermal behaviour of the ni­ troxide radicals was examined by polarizing microscopy, differential scanning calorimetry as well as X-ray diffraction experiments. Temperature dependent magnetic susceptibility mea­surements were carried out in order to determine the magnetic properties of these nitroxide radicals. The majority of the radicals presented here show weak antiferromagnetic exchange interactions.


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