Origin and tuning of the magnetocaloric effect in the magnetic refrigerant<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mrow><mml:mtext>Mn</mml:mtext></mml:mrow><mml:mrow><mml:mn>1.1</mml:mn></mml:mrow></mml:msub><mml:msub><mml:mrow><mml:mtext>Fe</mml:mtext></mml:mrow><mml:mrow><mml:mn>0.9</mml:mn></mml:mrow></mml:msub><mml:mrow><mml:mo>(</mml:mo><mml:mrow><mml:msub><mml:mtext>P</mml:mtext><mml:mrow><mml:mn>0.8</mml:mn></mml:mrow></mml:msub><mml:msub><mm

Liu, Danmin; Yue, Ming; Zhang, Jiuxing; McQueen, Tyrel M.; Lynn, J. W.; Wang, Xiaolu; Chen, Ying; Li, Jiying; Cava, R. J.; Liu, Xubo; Altounian, Z.; Huang, Q.

doi:10.1103/physrevb.79.014435

Cited by 73 publications

(54 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Repeating this process for all 11 samples, the variation of ΔT coex as function of the applied magnetic field was obtained. It has been shown that the coexistence of the PM and FM phases in the temperature interval T coex is due to the inhomogeneity of the distribution of Ge atoms in the structure [9,10]. It follows, therefore, that the system will have small values of B end when the chemical inhomogeneity is reduced or eliminated by means of appropriate preparation and treatment of the samples [9,10].…”

Section: Ammentioning

confidence: 99%

“…2b with the FM phase fractions as a function of temperature (frac(FM)-T) derived from monitoring the integrated intensities of the (001) neutron Bragg reflection upon warming and cooling. Note that the c-axis lattice parameters in the paramagnetic and ferromagnetic phases are quite different, so that (001) PM and (001) FM are easily distinguishable with NPD [9,10]. The ferromagnetic transition temperature (T c ), thermal hysteresis (T hys ), and the temperature range of coexistence of the PM and FM phases (T coex ) [9,10] are given in the figure and are quite different for the three samples.…”

Section: Temperature and Field Induced Transitionmentioning

confidence: 99%

“…Note that the c-axis lattice parameters in the paramagnetic and ferromagnetic phases are quite different, so that (001) PM and (001) FM are easily distinguishable with NPD [9,10]. The ferromagnetic transition temperature (T c ), thermal hysteresis (T hys ), and the temperature range of coexistence of the PM and FM phases (T coex ) [9,10] are given in the figure and are quite different for the three samples. For each sample, the corresponding values of T C derived from the M-T and Frac(FM)-T curves are in good agreement on both warming and cooling.…”

Section: Temperature and Field Induced Transitionmentioning

confidence: 99%

“…9 demonstrate that the largest crystallites transform first, leaving the smaller crystallites in the PM phase; hence the broadened Bragg peak. In addition, we know from previous work that compositional variations affect both the transition temperature and phase fraction that converts [8][9][10][11]. We have therefore undertaken additional characterization and annealing studies in order to unravel these two contributions to the performance of the material and to establish a procedure to improve the performance.…”

Section: Effects Of Crystallite Size and Inhomogeneities Of Compositimentioning

confidence: 99%

“…Leitão,et al reported [8] that the T c of the Fe rich side of the (Mn,Fe) 2 (P,Ge) system is easy to tune with careful manipulation of Fe and Ge content, but the ferro-paramagnetic transition sharpness decreases in the compounds [8]. In our previous work [9][10][11] the crystal and magnetic structures for the compound with composition Mn 1.1 Fe 0.9 (P 0.8 Ge 0.2 ) and Mn 1.1 Fe 0.9 (P 0.76 Ge 0.24 ) were determined by neutron powder diffraction (NPD). These compounds have the Fe 2 P-type structure (space group P 6 2m) and undergo a combined first-order structural and magnetic transition from a paramagnetic (PM) to a ferromagnetic (FM) phase.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

A pathway to optimize the properties of magnetocaloric Mn2-xFexP1-yGey for magnetic refrigeration

Liu

Zhang

Zhou

et al. 2016

Journal of Alloys and Compounds

View full text Add to dashboard Cite

Magnetocaloric materials can be useful in magnetic refrigeration applications, but to be practical the magneto-refrigerant needs to have a very large magnetocaloric effect (MCE) near room temperature for modest applied fields (<2 Tesla) with small hysteresis and magnetostriction, and should have a complete magnetic transition, be inexpensive, and environmentally friendly. One system that may fulfill these requirements is Mn x Fe 2-x P 1-y Ge y , where a combined first-order structural and magnetic transition occurs between the high temperature paramagnetic and low temperature ferromagnetic phase. We have used neutron diffraction, differential scanning calorimetry, and magnetization measurements to study the effects of Mn and Ge location in the structure on the ordered magnetic moment, MCE, and hysteresis for a series of compositions of the system near optimal doping. The diffraction results indicate that the Mn ions located on the 3f site enhance the desirable properties, while those located on the 3g sites are detrimental. The entropy changes measured directly by calorimetry can exceed 40 J/kg·K. The phase fraction that transforms, hysteresis of the transition, and entropy change can be controlled by both the compositional homogeneity and the particle size, and an annealing procedure has been developed that substantially improves the performance of all three properties of the material. On the basis of these results we have identified a pathway to optimize the MCE properties of this system for magnetic refrigeration applications.

show abstract

Section: Ammentioning

confidence: 99%

Section: Temperature and Field Induced Transitionmentioning

confidence: 99%

Section: Temperature and Field Induced Transitionmentioning

confidence: 99%

Section: Effects Of Crystallite Size and Inhomogeneities Of Compositimentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

A pathway to optimize the properties of magnetocaloric Mn2-xFexP1-yGey for magnetic refrigeration

Liu

Zhang

Zhou

et al. 2016

Journal of Alloys and Compounds

View full text Add to dashboard Cite

show abstract

Ball milling as a way to produce magnetic and magnetocaloric materials: a review

et al. 2017

View full text Add to dashboard Cite

Ball milling (BM) is a well-established technique for producing different materials in powder shape. Dynamical analysis of BM helps to optimize the process through simple but general relations (e.g definition of an equivalent milling time). Concerning the area of study of magnetocaloric effect (MCE), BM is used in different ways: as a single step process (mechanical alloying), as an initial step to enhance mixing of the elements (e.g. to speed up the formation of the desired intermetallic phase) or as a final step (e.g. hydriding of La-Fe-Si). In this contribution, besides a simple description of the effects of some geometrical parameters on the power released during BM and a short review of the BM contribution to the research field of MCE, we will discuss the effect of the microstructure of the starting material and the granular shape inherent to BM on magnetic materials exhibiting MCE.

show abstract

Structure and magnetic properties of Mn1.2Fe0.8P0.76Ge0.24 annealed alloy

Yue

Zhao

et al. 2012

Rare Metals

View full text Add to dashboard Cite

Origin and tuning of the magnetocaloric effect in the magnetic refrigerantMn1.1Fe0.9(P0.8

Cited by 73 publications

References 18 publications

A pathway to optimize the properties of magnetocaloric Mn2-xFexP1-yGey for magnetic refrigeration

A pathway to optimize the properties of magnetocaloric Mn2-xFexP1-yGey for magnetic refrigeration

Ball milling as a way to produce magnetic and magnetocaloric materials: a review

Structure and magnetic properties of Mn1.2Fe0.8P0.76Ge0.24 annealed alloy

Contact Info

Product

Resources

About