scholarly journals Tuning the Magnetocaloric Properties of the La(Fe,Si)13 Compounds by Chemical Substitution and Light Element Insertion

2021 ◽  
Vol 7 (1) ◽  
pp. 13
Author(s):  
Valérie Paul-Boncour ◽  
Lotfi Bessais
Keyword(s):  
Curie Temperature ◽  
Room Temperature ◽  
Light Element ◽  
Magnetic Entropy ◽  
Element Insertion ◽  
Chemical Substitution ◽  
Magnetocaloric Properties ◽  
Methods Of Synthesis ◽  
Giant Magnetocaloric Effect ◽  
Curie Temperature Tc

LaFe13−xSix compounds exhibit a giant magnetocaloric effect and they are considered as a good magnetocaloric working substance for an environmentally friendly cooling technique. Nevertheless as the Curie temperature TC is around 200 K, it is necessary to tune TC near room temperature for magnetic refrigeration. In this work we present a review of the various methods of synthesis and shaping of the LaFe13−xSix type compounds as well as the influence of chemical substitution, light element insertion or combination of both on TC, magnetic entropy and adiabatic temperature variation (ΔSM and ΔTad), and stability upon cycling. The advantages and drawbacks of each method of preparation and type of element substitution/insertion are discussed. The implementation of these NaZn13 type materials in active magnetic refrigerator is presented and their performances are compared to that of Gd in prototypes.

Structural and Magnetocaloric Properties of Ball Milled LaFe13−xSix(H,C)y

MRS Advances ◽  
2017 ◽  
Vol 2 (56) ◽  
pp. 3447-3452
Author(s):  
L. Bessais ◽  
M. Phejar ◽  
V. Paul-Boncour
Keyword(s):  
Curie Temperature ◽  
Magnetic Moments ◽  
Synthesis Method ◽  
Annealing Treatment ◽  
Interstitial Site ◽  
High Energy ◽  
Magnetocaloric Properties ◽  
Magnetovolume Effect ◽  
Short Annealing ◽  
Giant Magnetocaloric Effect

ABSTRACTLaFe13−xSix compounds display a giant magnetocaloric effect near 200 K. The insertion of light elements (H, C) is used to improve the Curie temperature near ambient temperature for magnetic refrigeration applications. We have developed a synthesis method with a short annealing treatment compared to classical melting techniques. The parent intermetallic alloys were synthesized by high energy ball milling. The insertion of H atoms was carried out using a Sievert apparatus and the carbon atom was inserted by solid/solid reaction. Moreover, structural and magnetic results were carried out by neutron diffraction and Mössbauer spectrometry for H content (y = 0.7,1.5) and C content (y = 0.7). The cell parameter and the Fe magnetic moments versus temperature are determined. The misunderstanding on interstitial site is clarified. The magnetovolume effect on the Curie temperature is explained by combination of the structural and magnetic properties. The advantages and drawbacks of each type of element insertion are discussed.

The Magnetic Entropy Changes in Gd1-xCrx Alloys

2005 ◽  
Vol 475-479 ◽  
pp. 2267-2270 ◽  
Author(s):  
Song Ling Huang ◽  
Dun Hui Wang ◽  
Zhi Da Han ◽  
S.K. Ren ◽  
Zheng Hua Su ◽  
...  
Keyword(s):  
Curie Temperature ◽  
Room Temperature ◽  
Magnetic Refrigeration ◽  
Magnetic Entropy ◽  
Entropy Changes ◽  
Arc Melting ◽  
Magnetic Refrigerant ◽  
Room Temperature Magnetic Refrigeration ◽  
High Level ◽  
Curie Temperatures

A series of Gd1-xCrx (x=0.01,0.03,0.05 and 0.07) alloys have been prepared by arc melting. After introducing a small quantity of Cr into Gd, the Curie temperatures of these alloys increase. Magnetic entropy changes at the Curie temperature of Gd1-xCrx (x=0.01, 0.03, 0.05) alloys are nearly the same as that of Gd. However, compared with Gd, the magnetic entropy changes of Gd1-xCrx (x=0.01, 0.03, 0.05) alloys remain at a high level in a wider temperature range. So Gd1-xCrx (x=0.01, 0.03, 0.05) alloys are more suitable as magnetic refrigerant to be used in Ericsson Recycle for room temperature magnetic refrigeration. Our results and the fact that Cr is quite cheaper than Gd, suggest that Gd1-xCrx alloys maybe utilized as refrigerant in room temperature magnetic refrigeration.

scholarly journals Effect of Co/Ni Substituting Fe on Magnetocaloric Properties of Fe-Based Bulk Metallic Glasses

Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 950
Author(s):  
Jia Guo ◽  
Lei Xie ◽  
Cong Liu ◽  
Qiang Li ◽  
Juntao Huo ◽  
...  
Keyword(s):  
Metallic Glasses ◽  
Amorphous Alloys ◽  
Magnetic Entropy Change ◽  
Bulk Metallic Glasses ◽  
Entropy Change ◽  
Magnetic Entropy ◽  
Glass Forming ◽  
Magnetic Refrigerant ◽  
Magnetocaloric Properties ◽  
Curie Temperature Tc

In this work, Fe80-xMxP13C7 (M = Co, Ni; x = 0, 5 and 10 at.%) bulk metallic glasses (BMGs) were prepared, and the effect of the Co/Ni elements substitution for Fe on the magnetocaloric properties of Fe80P13C7 BMG has been investigated systematically. The Curie temperature (TC) of the present Fe-based BMGs increases with the substitution of Fe by Co/Ni. The magnetic entropy change (ΔSM) of the present Fe-based BMGs increases first and then decreases with the increase of Fe substituted by Co, but monotonically decreases with the increase of Fe substituted by Ni. Among the present Fe-based BMGs, the Fe75Co5P13C7 BMG exhibits the maximum ΔSM value of 5.21 J kg−1 K−1 at an applied field of 5 T, which is the largest value among Fe-based amorphous alloys without any rare earth elements reported so far. The present Fe-based BMGs exhibit the large glass forming ability, tunable TC and enhanced ΔSM value, which are beneficial for magnetic refrigerant materials.

scholarly journals Compositional Dependence of Curie Temperature and Magnetic Entropy Change in the Amorphous Tb–Co Ribbons

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 1002
Author(s):  
Xin Wang ◽  
Ding Ding ◽  
Li Cui ◽  
Lei Xia
Keyword(s):  
Curie Temperature ◽  
Linear Relationship ◽  
Metallic Glasses ◽  
Amorphous Alloys ◽  
Magnetic Entropy Change ◽  
Alloy Composition ◽  
Entropy Change ◽  
Magnetic Entropy ◽  
Compositional Dependence ◽  
Curie Temperature Tc

The Curie temperature (Tc) and magnetic entropy change (−ΔSm), and their relationship to the alloy composition of Tb–Co metallic glasses, were studied systematically in this paper. It was found that, in contrast to the situation in amorphous Gd–Co ribbons, the dependence of Tc on Tb content and the maximum −ΔSm vs. Tc -2/3 plots in Tb–Co binary amorphous alloys do not follow a linear relationship, both of which are supposed to be closely related to the non-linear compositional dependence of Tb–Co interaction due to the existence of orbital momentum in Tb.

scholarly journals Tuning the Room Temperature Ferromagnetism in Fe5GeTe2 by Arsenic Substitution

2D Materials ◽  
2021 ◽  
Author(s):  
Andrew May ◽  
Jiaqiang Yan ◽  
Raphael Hermann ◽  
Mao-Hua Du ◽  
Michael A McGuire
Keyword(s):  
Magnetic Properties ◽  
Curie Temperature ◽  
Room Temperature ◽  
Room Temperature Ferromagnetism ◽  
Fine Tuning ◽  
The Individual ◽  
Curie Temperature Tc ◽  
Antiferromagnetic Behavior ◽  
Magnetic Sublattices

Abstract In order to tune the magnetic properties of the cleavable high-Curie temperature ferromagnet Fe5-xGeTe2, the effect of increasing the electron count through arsenic substitution has been investigated. Small additions of arsenic (2.5 and 5%) seemingly enhance ferromagnetic order in polycrystalline samples by quenching fluctuations on one of the three magnetic sublattices, whereas larger As concentrations decrease the ferromagnetic Curie temperature (TC) and saturation magnetization. This work also describes the growth and characterization of Fe4.8AsTe2 single crystals that are structurally analogous to Fe5-xGeTe2 but with some phase stability complications. Magnetization measurements reveal dominant antiferromagnetic behavior in Fe4.8AsTe2 with a Neel temperature of TN ≈42K. A field-induced spin-flop below TN results in a switch from negative to positive magnetoresistance, with significant hysteresis causing butterfly-shaped resistance loops. In addition to reporting the properties of Fe4.8GeTe2, this work shows the importance of manipulating the individual magnetic sublattices in Fe5-xGeTe2 and motivates further efforts to control the magnetic properties in related materials by fine tuning of the Fermi energy or crystal chemistry.

Observation of Griffiths Phase, Critical Exponent Analysis and High Magnetocaloric Effect Near Room Temperature at Low Magnetic Field in V doped La0.7Sr0.3MnO3

2022 ◽  
Author(s):  
Jagadish Kumar Galivarapu ◽  
Ashika Jose ◽  
Erappanal Padmanabhan Jinu ◽  
Thirumalainaidu Thiagarajan Saravanan ◽  
Senthil Kumar Eswaran ◽  
...  
Keyword(s):  
Magnetic Fields ◽  
Curie Temperature ◽  
Critical Exponent ◽  
Critical Exponents ◽  
Room Temperature ◽  
Magnetic Entropy Change ◽  
Entropy Change ◽  
Magnetic Entropy ◽  
Griffiths Phase ◽  
Vanadium Doping

Abstract We report on observation of Griffiths phase, high magnetocaloric properties at low magnetic fields and temperature dependent critical exponents of La0.7Sr0.3VxMn1-xO3 (x=0, 0.05 & 0.1) perovskite bulk materials. The Curie temperature (TC) of pure La0.7Sr0.3MnO3 is seen to be 368.7 K and decreases towards room temperature (342.2 K) by 10 mol% vanadium doping at the Mn site. Vanadium doping leads to enhancement in magnetic entropy change (-SM) from 1 Jkg-1K-1to 1.41 Jkg-1K-1. Vanadium doping at Mn site leads to the formation of Griffiths phase, a magnetic disorder due to the co-existence of paramagnetic matrix and short range ferromagnetic clusters. X-ray photoelectron spectroscopy analysis confirm the presence of mixed valance V4+/V5+along with Mn3+/ Mn4+ ions contributing to various double exchange interactions. Nature of phase transitions and magnetic interactions are analyzed by evaluating critical exponents and. All the samples show second-order ferromagnetic (FM) to paramagnetic (PM) phase transition, confirmed from the modified Arrott’s plots and critical exponent analysis carried out using Kouvel-Fisher method. Enhancement in magnetic entropy change along with the decrease in Curie temperature towards room temperature by vanadium doping in the La0.7Sr0.3MnO3 oxides indicates the possible application of these materials for the magnetic refrigeration at low magnetic fields.

Effect of Fe on the Martensitic Transition, Magnetic and Magnetocaloric Properties in Ni-Mn-In Melt-spun Ribbons

2016 ◽  
Vol 66 (4) ◽  
pp. 403 ◽  
Author(s):  
D.M. Raj kumar ◽  
N.V. Rama Rao ◽  
S. Esakki Muthu ◽  
S. Arumugam ◽  
M. Manivel Raja ◽  
...  
Keyword(s):  
Room Temperature ◽  
Magnetic Entropy Change ◽  
Thermal Hysteresis ◽  
Entropy Change ◽  
Austenite Phase ◽  
High Magnetic Fields ◽  
Martensitic Transition ◽  
Magnetic Entropy ◽  
Fe Content ◽  
Magnetocaloric Properties

The effect of Fe on the martensitic transitions, magnetic and inverse magnetocaloric effect in Ni47Mn40-xFexIn13 ribbons (x = 1, 2, 3 and 5) has been investigated. All the ribbon compositions under study have shown the presence of austenite phase at room temperature. The variation of martensitic transition with the increase in Fe-content is non-monotonic. The thermal hysteresis of the martensitic transition increased with the increase in Fe-content. The martensitic transitions shifted to lower temperatures in the presence of high magnetic fields. A maximum magnetic entropy change (∆SM) of 50 Jkg-1K-1 has been achieved in the Ni47Mn38Fe2In13 (x = 1) ribbon at 282 K for an applied field of 5 T.

Piezoelectric and Dielectric Properties of MnO2-Modified Bi(Mg1/2Ti1/2)O3–PbTiO3

2011 ◽  
Vol 415-417 ◽  
pp. 1983-1987
Author(s):  
Xiao Na Wang ◽  
Qing Chi Sun ◽  
Wei Bing Ma ◽  
Tao Liu ◽  
Yong Zhang ◽  
...  
Keyword(s):  
Dielectric Properties ◽  
Curie Temperature ◽  
Room Temperature ◽  
Piezoelectric Properties ◽  
High Curie Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Stable Temperature ◽  
Curie Temperature Tc ◽  
Dielectric And Piezoelectric Properties

We reported that Bi(Mg1/2Ti1/2)O3–PbTiO3(BMT-PT) systems had high piezoelectric, dielectric performances and high Curie temperature. The phase structure of the system was identified by X-ray diffraction analysis. The piezoelectric and dielectric properties were also investigated. The results showed that 0.6BMT–0.4PT (Mg/Ti = 0.5:0.5) with 1mol% MnO2was the optimum composition which exhibited the highest curie temperature Tc = 511 °C and the stable temperature of dielectric loss reached to 500 °C. Further, the dielectric and piezoelectric properties of this composition were given as follows:kp = 22.5%;εr= 734; room temperature d33= 131.3 pC/N; tanδ = 1.96%.

The Magnetocaloric Properties of (Mn1-XFeX)5Sn3 Compounds Prepared in Magnetic Environment

2011 ◽  
Vol 299-300 ◽  
pp. 520-524 ◽  
Author(s):  
Jian Huang ◽  
Jie Xiang ◽  
Ce Zhi ◽  
Xue Zhen Wang ◽  
Xue Ling Hou
Keyword(s):  
Crystal Structure ◽  
Powder Metallurgy ◽  
Curie Temperature ◽  
Magnetic Entropy Change ◽  
Entropy Change ◽  
Lattice Parameter ◽  
Powder Metallurgy Method ◽  
Magnetic Entropy ◽  
Magnetocaloric Properties ◽  
Cell Volumes

The crystal structure, microstructure, Curie temperature and magnetocaloric properties of (Mn1-xFex)5Sn3 (x=0.1~0.5) alloys were studied in this paper. The alloys were prepared by powder metallurgy method with magnetic pressing and magnetic sintering. All samples crystallize in the hexagonal InNi2-type structure with space group P63/mmc. The lattice parameter, cell volumes of the (Mn1-xFex)5Sn3 decrease with increasing x, while the Curie temperature of these alloys increases almost linearly with increasing x. All samples exhibit a moderate magnetocaloric effect, and the curves of magnetic entropy change are flat in a wide temperature range, which is suitable for the Ericsson cycle.

scholarly journals Новые магнитные материалы на основе соединений RNi для криогенной техники

2020 ◽  
Vol 46 (6) ◽  
pp. 51
Author(s):  
В.Б. Чжан ◽  
И.С. Терёшина ◽  
А.А. Курганская ◽  
С.А. Лушников ◽  
В.Н. Вербецкий ◽  
...  
Keyword(s):  
Low Temperature ◽  
Curie Temperature ◽  
Magnetocaloric Effect ◽  
Temperature Region ◽  
Partial Substitution ◽  
Temperature Range ◽  
Magnetocaloric Properties ◽  
Cryogenic Engineering ◽  
Significant Change ◽  
Curie Temperature Tc

Magnetocaloric properties of compounds Gd(Ni0.98Si0.02), Dy(Ni0.95Si0.05) and their hydrides Gd(Ni0.98Si0.02)H3, Dy(Ni0.95Si0.05)H4 were investigated in the temperature range 2 – 100K. It was found that partial substitution of Ni atoms by Si atoms, as well as subsequent hydrogenation can lead to a significant change in the Curie temperature (TC), the magnetocaloric effect, and the temperature at which the maximum MCE (Tmax) is observed. It is shown that the TC and Tmax of the hydrides are shifted by several degrees to the low temperature region with increasing or maintaining the MCE, which can significantly expand the application of such materials in cryogenic engineering.

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