Improvement in the magnetocaloric properties of sintered La(Fe,Si)13 based composites processed by La-Co grain boundary diffusion

Zhong, Xichun; Peng, Daoling; Dong, X.T.; Huang, Jiajin; Zhang, H.; Jiao, Dongling; Zhang, H.; Liu, Zhongwu; Ramanujan, R.V.

doi:10.1016/j.jallcom.2018.11.395

Cited by 21 publications

(13 citation statements)

References 33 publications

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“…A small amount of CeFe 7 -type phase (light grey) appeared in the binder bonded composites. The formation enthalpy of CeCo 7 (−10.704 kJ/mol calculated by the modified Miedema (ZSL's Model) [36] is more negative than that of LaCo 13 (−5.79 kJ/mol) [34], favoring the formation of the 1:7 phase. The EDS map results of the LaFe 11.6 Si 1.4 /5 wt.%Ce 2 Co 7 sintered composites are shown in the inset of Figure 2c, uniform diffusion of Co occurred in the 1:13 phase.…”

Section: Microstructure Evolutionmentioning

confidence: 94%

“…The sintering temperature is close to the optimum formation temperature of the 1:13 phase [55], which may bring about 1:13 phase formation and decrease the α-Fe phase content (Table 1), resulting in the formation of a nonstoichiometric Fe deficient 1:13 phase (Table 2). This Fe-deficient 1:13 phase has elevated T C (Table 2), which weakens the first order magnetic transition (FOMT) and lowers the (−∆S M ) max [7,18,34]. The binder-free composites exhibited the maximum magnetic entropy change (−∆S M ) max of 5.2 and 8.8 J/kg•K under applied field changes of 0-2 and 0-5 T, respectively (Table 2).…”

Section: Thermal Conductivity Mechanical and Magnetic Propertiesmentioning

confidence: 99%

“…La-Co alloys [34,35] have been used as binder due to the low enthalpy of formation of the LaCo 13 phase (-5.79 kJ/mol) [36], lower La-Fe binary phase content and the low melting point of a La-based eutectic alloy [37]. Based on grain boundary diffusion (GBD) theory [38], Co diffusion occurs through annealing after hot pressing [34,39]. During annealing, Co can diffuse into the 1:13 matrix, influencing the magnetic and magnetocaloric properties and promoting the formation of the 1:13 phase.…”

Section: Introductionmentioning

confidence: 99%

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One-Step Sintering Process for the Production of Magnetocaloric La(Fe,Si)13-Based Composites

Zhong

Dong

Huang

et al. 2022

Metals

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A one-step sintering process was developed to produce magnetocaloric La(Fe,Si)13/Ce-Co composites. The effects of Ce2Co7 content and sintering time on the relevant phase transformations were determined. Following sintering at 1373 K/30 MPa for 1–6 h, the NaZn13-type (La,Ce)(Fe,Co,Si)13 phase formed, the mass fraction of α-Fe phase reduced and the CeFe7-type (La,Ce)(Fe,Co,Si)7 phase appeared. The mass fraction of the (La,Ce)(Fe,Co,Si)7 phase increased, and the α-Fe phase content decreased with increasing Ce2Co7 content. However, the mass fraction of the (La,Ce)(Fe,Co,Si)7 phase reduced with increasing sintering time. The EDS results showed a difference in concentration between Co and Ce at the interphase boundary between the 1:13 phase and the 1:7 phase, indicating that the diffusion mode of Ce is reaction diffusion, while that of Co is the usual vacancy mechanism. Interestingly, almost 100 % single phase (La,Ce)(Fe,Co,Si)13 was obtained by appropriate Ce2Co7 addition. After 6 h sintering at 1373 K, the Ce and Co content in the (La,Ce)(Fe,Co,Si)13 phase increased for larger Ce2Co7 content. Therefore, the Curie temperature increased from 212 K (binder-free sample) to 331 K (15 wt.% Ce2Co7 sample). The maximum magnetic entropy change (−∆SM)max decreased from 8.8 (binder-free sample) to 6.0 J/kg∙K (15 wt.% Ce2Co7 sample) under 5 T field. High values of compressive strength (σbc)max of up to 450 MPa and high thermal conductivity (λ) of up to 7.5 W/m∙K were obtained. A feasible route to produce high quality La(Fe,Si)13 based magnetocaloric composites with large MCE, good mechanical properties, attractive thermal conductivity and tunable TC by a one-step sintering process has been demonstrated.

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Section: Microstructure Evolutionmentioning

confidence: 94%

Section: Thermal Conductivity Mechanical and Magnetic Propertiesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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One-Step Sintering Process for the Production of Magnetocaloric La(Fe,Si)13-Based Composites

Zhong

Dong

Huang

et al. 2022

Metals

Self Cite

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“…Compressive stress–strain curves of Ni 48– x Mn 38 Sn 9 Cu 6 ( x = 0, 6, 8, 10, and 12) alloys at room temperature (a) and the maximum values of the maximum compressive stress and strain for the prevailing MCE materials (b). ,,− …”

Section: Realization By Experimentsmentioning

confidence: 99%

Computation-Guided Design of Ni–Mn–Sn Ferromagnetic Shape Memory Alloy with Giant Magnetocaloric Effect and Excellent Mechanical Properties and High Working Temperature via Multielement Doping

Zhang

Tan

Zhao

et al. 2019

ACS Appl. Mater. Interfaces

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Ni–Mn–Sn ferromagnetic shape memory alloys (FSMAs) have promise for application in efficient solid-state refrigeration. However, the simultaneous achievement of giant magnetocaloric effect (MCE) and excellent mechanical properties and high working temperature in these materials is always the challenge. Computation-guided materials design techniques provide an efficient way to design and identify new magnetocaloric materials. Herein, a new strategy of multidoping is presented. First, we conduct a detailed and comprehensive first-principles study and predict that Ni–Mn–Sn FSMAs with co-doping 6.25 atom % Cu and 6.25–12.5 atom % Co can realize the multiobjective optimization of magnetocaloric material. Then, it is confirmed by experiment and we report on Ni40Co8Mn37Sn9Cu6 FSMA exhibiting a large magnetic entropy change (34.8 J/(kg K)) of a large value in the prevalent MCE materials at high temperature (∼344 K) and whose compression stress and strain (∼1072.0 MPa and ∼11.9%) are both the largest among Ni–Mn-based MCE materials. Notably, the effect of Co and Cu doping is not simply stacked because they play opposite roles in Curie temperature (T C) and martensitic transformation temperature (T M). So, achieving the balance of their effect to combine their merits in a very narrow window is the key step. This approach of multielement doping holds promise to be extended to other magnetocaloric materials to enhance their multiple properties simultaneously.

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“…Magnetic refrigeration technology has attracted worldwide attention because of its high energy efficiency and environmental friendliness. , By magnetizing and demagnetizing a magnetic refrigerant near the Curie temperature T C , the magnetic refrigerant can release or consume heat to or from the environment, which can be utilized to build a heat pump for refrigeration applications. − La(Fe,Si) 13 -based alloys with cubic NaZn 13 -type structure (1:13 phase) are considered to be a promising candidate of magnetic refrigerant for the magnetic refrigeration technology because of their giant magnetocaloric effects (MCEs), adjustable Curie temperature, and lower cost. − As a solid-state magnetic refrigerant, the heat exchange between La(Fe,Si) 13 -based alloys and the load must be done through a flowing heat transfer fluid which is usually distilled water . Therefore, the corrosion resistance of the La(Fe,Si) 13 -based alloys in water is crucial to the performance of the magnetic refrigerant …”

Section: Introductionmentioning

confidence: 99%

Corrosion Behavior of Nonstoichiometric La(Fe,Si)₁₃-Based Alloys

et al. 2019

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The magnetic refrigerants in the magnetic refrigeration machine usually work in the water. Therefore, the corrosion resistance of magnetic refrigerants in water is very important. In this paper, nonstoichiometric LaFe11.5Si1.5C0.15 + X (X: nonstoichiometric additions) alloys are prepared, leading to a specific impurity phase accompanying the matrix 1:13 phase. The effects of the specific impurity phase on the corrosion behavior of the alloys are investigated. This study shows that the main corrosion mechanism of the alloys containing impurity phases is microgalvanic corrosion. The galvanic current density of these alloys is controlled by the difference in electrochemical properties between each impurity phase and the matrix 1:13 phase. Weight loss experiments show that the LaFe11.5Si1.5C0.15 + (La5Si3)0.1 alloy suffers the most serious corrosion in the distilled water among the investigated alloys. However, after doping Ni in the LaFe11.5Si1.5C0.15 + (La5Si3) y (y = 0.05, 0.1) alloys, Ni element enters La-rich phase and changes its electrochemical properties. It results in the decrease of the electrochemical potential difference between the La-rich phase and the 1:13 phase, which makes the alloy have the best corrosion resistance among the investigated alloys, but even small amounts of Ni in the 1:13 phase would cause a decrease in the maximum magnetic entropy change (|ΔS|max). On behalf of balancing the corrosion resistance and magnetocaloric effects, the LaFe11.5Si1.5C0.15 + (La5Si3 + Ni)0.05 alloy with a trace amount of La5Si3 and Ni additions is tested and proven to be a good candidate for magnetic refrigerants. The corrosion resistance is improved, while the |ΔS|max only suffers a minimal change for the alloy. In addition, the LaFe11.5Si1.5C0.15 + Nb0.1 alloy consisting of the Fe2Nb phase and matrix 1:13 phase shows a slight improvement in corrosion resistance with higher |ΔS|max. The results indicate that doping certain elements to the impurity phase makes it possible to improve the corrosion resistance while maintaining its maximum magnetic entropy change.

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Improvement in the magnetocaloric properties of sintered La(Fe,Si)13 based composites processed by La-Co grain boundary diffusion

Cited by 21 publications

References 33 publications

One-Step Sintering Process for the Production of Magnetocaloric La(Fe,Si)13-Based Composites

One-Step Sintering Process for the Production of Magnetocaloric La(Fe,Si)13-Based Composites

Computation-Guided Design of Ni–Mn–Sn Ferromagnetic Shape Memory Alloy with Giant Magnetocaloric Effect and Excellent Mechanical Properties and High Working Temperature via Multielement Doping

Corrosion Behavior of Nonstoichiometric La(Fe,Si)₁₃-Based Alloys

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Improvement in the magnetocaloric properties of sintered La(Fe,Si)13 based composites processed by La-Co grain boundary diffusion

Cited by 21 publications

References 33 publications

One-Step Sintering Process for the Production of Magnetocaloric La(Fe,Si)13-Based Composites

One-Step Sintering Process for the Production of Magnetocaloric La(Fe,Si)13-Based Composites

Computation-Guided Design of Ni–Mn–Sn Ferromagnetic Shape Memory Alloy with Giant Magnetocaloric Effect and Excellent Mechanical Properties and High Working Temperature via Multielement Doping

Corrosion Behavior of Nonstoichiometric La(Fe,Si)13-Based Alloys

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Product

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Corrosion Behavior of Nonstoichiometric La(Fe,Si)₁₃-Based Alloys