Enhanced Curie temperature and magnetic entropy change of Gd63Ni37 amorphous alloy by Co substitution

Small amount of Ni was added in the [Formula: see text] binary alloy to replace the Co element for improving the formability and magnetic properties of the binary amorphous alloy. It was found that the glass formability of the [Formula: see text] amorphous alloy was significantly improved by Ni addition. The Curie temperature [Formula: see text] of the [Formula: see text] metallic glasses decreases with the Ni addition, and the maximum magnetic entropy change [Formula: see text] was also improved. The mechanism for the effect of adding a small quantity of Ni on the [Formula: see text] and [Formula: see text] of the [Formula: see text] amorphous alloy was studied.

Download Full-text

Magnetic properties of the non-stoichiometric TbCo2Nix alloys

EPJ Web of Conferences ◽

10.1051/epjconf/201818504021 ◽

2018 ◽

Vol 185 ◽

pp. 04021

Author(s):

Alexander Inishev ◽

Evgeny Gerasimov ◽

Nikolay Mushnikov ◽

Pavel Terentev ◽

Vasily Gaviko

Keyword(s):

Magnetic Properties ◽

Curie Temperature ◽

Concentration Dependence ◽

Magnetic Moment ◽

Magnetic Entropy Change ◽

Entropy Change ◽

Magnetic Entropy ◽

Thermodynamic Relation ◽

Temperature Dependences

The magnetic and magnetothermal properties of the non-stoichiometric TbCo2Nix (0 ≤ x ≤ 0.2) alloys were studied. It was found that the concentration dependence of the Curie temperature and magnetic moment of the 3d-sublattice have a maximum at x = 0.025. The obtained experimental magnetic properties of the TbCo2Nix alloys were discussed under assumption that the Co magnetic moment in the compounds changes with increasing x. The magnetic entropy change was determined using the temperature dependences of the magnetization and Maxwell’s thermodynamic relation. The obtained results for TbCo2Nix were compared with those for the ErCo2Mnx alloys.

Download Full-text

Study of Magnetic Transition and Magnetocaloric Effect in La1-xSrxMnO3 (0.20≤ x ≤0.35) Compounds

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.378.225 ◽

2013 ◽

Vol 378 ◽

pp. 225-229 ◽

Cited By ~ 1

Author(s):

Yeong Seung Jeong ◽

M.S. Anwar ◽

Faheem Ahmed ◽

Seung Rok Lee ◽

Bon Heun Koo

Keyword(s):

Curie Temperature ◽

Magnetic Entropy Change ◽

Perovskite Phase ◽

Magnetic Transition ◽

Entropy Change ◽

Solid State Reaction Method ◽

Magnetic Entropy ◽

Conventional Solid State Reaction ◽

Ionic Radii ◽

The Difference

We report the magnetic transition and large magnetic entropy change in Sr doped lanthanum manganites. Polycrystalline La1-xSrxMnO3(0.20x0.35) samples were prepared using the conventional solid-state reaction method. The results of X-ray diffraction indicates perovskite phase without any impurity. The magnetic study has revealed that the Curie temperature is influenced by Sr-concentration. The doping of Sr at La site affects the Mn-O bond length and Mn-O-Mn bond angle due to the difference in their ionic radii, consequently, the Curie temperature changed. A large magnetic entropy change has been observed for La0.8Sr0.2MnO3sample, the value of the maximum entropy change (SMmax) increases from 1.42 to 2.74 J/kgK as magnetic field increases from 1 to 2.5 T. This investigation suggests that La1-xSrxMnO3can be used as a potential magnetic refrigeration material.

Download Full-text

Large magnetic entropy change and adiabatic temperature rise of Fe85B12La3 amorphous alloy

Physica B Condensed Matter ◽

10.1016/j.physb.2020.412014 ◽

2020 ◽

Vol 583 ◽

pp. 412014

Author(s):

B.Z. Tang ◽

M.N. Song ◽

L.W. Huang ◽

D. Ding ◽

L. Xia

Keyword(s):

Amorphous Alloy ◽

Temperature Rise ◽

Magnetic Entropy Change ◽

Entropy Change ◽

Adiabatic Temperature ◽

Magnetic Entropy ◽

Adiabatic Temperature Rise

Download Full-text

Study on Influence of Ca2+ Ions Doping at a Site on Magnetic Properties and Magnetocaloric Effect of Nominal Compositions La1.4Sr1.6-xCaxMn2O7

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1120-1121.406 ◽

2015 ◽

Vol 1120-1121 ◽

pp. 406-413 ◽

Cited By ~ 1

Author(s):

Yun Zong ◽

Di Kang

Keyword(s):

Curie Temperature ◽

Manganese Oxides ◽

Magnetic Entropy Change ◽

Entropy Change ◽

Xrd Analysis ◽

Layered Perovskite ◽

Magnetic Entropy ◽

Doping Amount ◽

Space Group ◽

Room Temperature Magnetic Refrigeration

Polycrystalline layered perovskite manganese oxides La1.4Sr1.6-xCaxMn2O7 (x=0,0.2,0.4,0.8,1.0,1.4,1.6) samples is prepared using solid state reaction.The XRD analysis shows that La1.4Sr1.6-xCaxMn2O7 (0 ≤ x ≤ 0.8) samples are Sr3Ti2O7-type tetragonal structure with space group I4/mmm and forms a layered perovskite structure; for the 1.0≤ x ≤1.6 series of samples the main phase is ABO3 type orthorhombic structure with space group Pbnm.For small amount of Ca2+ ion-doped sample (x= 0.2,0.4), induce serious Jahn-Teller(J-T) distortion of MnO6 octahedral.For a large number of doping (1.0≤ x ≤1.6) samples, ferromagnetic - paramagnetic transition occurs near the Curie temperature (Tc) from low to high temperatures.With increasing doping amount, the magnetization reached maximum at x=1.4 samples.Maximum magnetic entropy change of the three samples(x=1.0,1.4,1.6) reaches 0.84, 1.20 and 2.28 J kg-1 K-1 at 320,268 and 215K near the Curie temperature, respectively. The large magnetic entropy change effect under low magnetic field of the sample makes it an optimal candidate of room temperature magnetic refrigeration materials.

Download Full-text

Field Dependence of the Refrigerant Capacity for La0.6Ca0.4MnO3 Manganite

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.154.163 ◽

2009 ◽

Vol 154 ◽

pp. 163-168 ◽

Cited By ~ 1

Author(s):

R.A. Szymczak ◽

Aleksandra Kolano-Burian ◽

Roman Kolano ◽

R. Puzniak ◽

V.P. Dyakonov ◽

...

Keyword(s):

Magnetic Field ◽

Curie Temperature ◽

Statistical Model ◽

Magnetic Entropy Change ◽

Entropy Change ◽

Relative Cooling Power ◽

Cooling Power ◽

Magnetic Entropy ◽

Refrigerant Capacity ◽

Jahn Teller

The magnetocaloric effect in La0.6Ca0.4MnO3 manganite has been investigated. The isothermal magnetization versus applied magnetic field at various temperatures in the vicinity of Curie temperature was measured, and the temperature dependence of magnetic entropy change was determined using Maxwell’s relation. This value is comparable to that in Gd. Nevertheless, the relative cooling power of La0.6Ca0.4MnO3 was shown to be considerably lower than that of Gd. The experimental results have been analyzed in frames of a phenomenological statistical model. This model considers explicitly Jahn-Teller interactions and allows prediction of the field dependences of the magnetic entropy change and the relative cooling power.

Download Full-text

Observation of a Broadened Magnetocaloric Effect in Partially Crystallized Gd60Co40 Amorphous Alloy

Metals ◽

10.3390/met11111741 ◽

2021 ◽

Vol 11 (11) ◽

pp. 1741

Author(s):

Ping Han ◽

Ziyang Zhang ◽

Jia Tan ◽

Xue Zhang ◽

Yafang Xu ◽

...

Keyword(s):

Amorphous Alloy ◽

Magnetocaloric Effect ◽

Magnetic Entropy Change ◽

Amorphous Matrix ◽

Thermodynamic Cycle ◽

Entropy Change ◽

Cooling Power ◽

Magnetic Entropy ◽

Amorphous Precursor ◽

Space Group

To investigate the effect of crystallization treatment on the structure and magnetocaloric effect of Gd60Co40 amorphous alloy, the melt-spun ribbons were annealed at 513 K isothermally for 20, 40 and 60 min. The results indicate that, with increasing annealing time, the Gd4Co3 (space group P63/m) and Gd12Co7 (space group P21/c) phases precipitated from the amorphous precursor in sequence. In particular, in the samples annealed for 40 and 60 min, three successive magnetic transitions corresponding to the phases of Gd4Co3, Gd12Co7 and remaining amorphous matrix were detected, which induced an overlapped broadened profile of magnetic entropy change (|ΔSM|) versus temperature. Under magnetic field changing from 0 to 5 T, |ΔSM| values of 6.65 ± 0.1 kg−1·K−1 and 6.44 ± 0.1 J kg−1·K−1 in the temperature spans of 180–196 K and 177–196 K were obtained in ribbons annealed for 40 and 60 min, respectively. Compared with the fully amorphous alloy, the enhanced relative cooling power and flattened magnetocaloric effect of partially crystallized composites making them more suitable for the Ericsson thermodynamic cycle.

Download Full-text

Achieving better glass-forming ability and magnetocaloric effect in the minor Zr-substituted Gd50Co50 amorphous alloy

International Journal of Modern Physics B ◽

10.1142/s0217979218500856 ◽

2018 ◽

Vol 32 (08) ◽

pp. 1850085

Author(s):

Li Yan Ma ◽

Liang Hua Gan ◽

Lei Xia ◽

JiaZheng Zhang ◽

Ding Ding

Keyword(s):

Amorphous Alloy ◽

Magnetocaloric Effect ◽

Melt Spinning ◽

Magnetic Entropy Change ◽

Thermodynamic Cycle ◽

Entropy Change ◽

Glass Forming Ability ◽

Magnetic Entropy ◽

Glass Forming ◽

Amorphous Ribbons

The glass-forming ability (GFA) and magnetic properties of the minor Zr-substituted Gd[Formula: see text]Co[Formula: see text] amorphous alloy were investigated. The Gd[Formula: see text]Co[Formula: see text]Zr2 amorphous ribbons prepared by melt-spinning show better GFA. With increasing minor Zr addition, the Gd[Formula: see text]Co[Formula: see text]Zr2 amorphous ribbons possessed higher magnetic entropy change peak ([Formula: see text]S[Formula: see text] = 3.9 Jkg[Formula: see text]K[Formula: see text], under 5 T) but lower Curie temperature (T[Formula: see text] = 231 K) than the Gd[Formula: see text]Co[Formula: see text] amorphous alloy. The mechanism for the improved GFA, magnetocaloric effect (MCE) and the decrease in T[Formula: see text] was investigated. Finally, combined with other Gd-based amorphous ribbons, the Gd[Formula: see text]Co[Formula: see text]Zr2 amorphous alloy was employed to construct amorphous composites to achieve a table-like magnetic entropy change profile, which can provide optimal efficiency when utilizing an Ericsson thermodynamic cycle.

Download Full-text