Magnetic Phase Diagram of the MnxFe2−xP1−ySiy System

Abstract

The phase diagram of the magnetocaloric MnxFe2−xP1−ySiy quaternary compounds was established by characterising the structure, thermal and magnetic properties in a wide range of compositions (for a Mn fraction of 0.3 ≤ x < 2.0 and a Si fraction of 0.33 ≤ y ≤ 0.60). The highest ferromagnetic transition temperature (Mn0.3Fe1.7P0.6Si0.4, TC = 470 K) is found for low Mn and high Si contents, while the lowest is found for low Fe and Si contents (Mn1.7Fe0.3P0.6Si0.4, TC = 65 K) in the MnxFe2−xP1−ySiy phase diagram. The largest hysteresis (91 K) was observed for a metal ratio close to Fe:Mn = 1:1 (corresponding to x = 0.9, y = 0.33). Both Mn-rich with high Si and Fe-rich samples with low Si concentration were found to show low hysteresis (≤2 K). These compositions with a low hysteresis form promising candidate materials for thermomagnetic applications.

Advanced Magnetocaloric Materials for Energy Conversion: Recent Progress, Opportunities, and Perspective

“…[148] They also observed a spin-density-wave (SDW) phase can co-exist with PM and FM phases in certain compositions of (Mn,Fe) 2 (P,Si) and the SDW-FM transition can be kinetically arrested at low temperature. [149] In addition, Dung and You et al [140,150] established the complete phase diagram of magnetocaloric Mn x Fe 2-x P 1-y Si y quaternary compounds and reported the corresponding magnetic/structural properties.…”

“…[ 149 ] In addition, Dung and You et al. [ 140,150 ] established the complete phase diagram of magnetocaloric Mn x Fe 2‐ x P 1‐ y Si y quaternary compounds and reported the corresponding magnetic/structural properties.…”

Comparison of the Magnetic and Structural Properties of MnFePSi Microwires and MnFePSi Bulk Alloy

“…MnFePSi alloys have emerged as a prominent and swiftly advancing category of magnetocaloric materials, drawing considerable attention in recent years due to their exceptional magnetic and structural properties [15][16][17][18]. This alloy stands out for its distinctive electronic structure, endowing it with remarkable attributes such as a high magnetocaloric effect (MCE) and substantial saturation magnetization [9,[18][19][20].…”

“…Furthermore, as we move towards an era of miniaturization and micro-scale technology, the development of MCE devices based on small-size MnFePSi particles, wires, ribbons, films, bi-and multilayers, and pillars becomes increasingly significant [15][16][17][18][19][20][21][22][23][24][25][26]. These compact and versatile forms of MnFePSi alloys open the door to a variety of technological applications, ranging from compact cooling devices in electronic components to portable cooling solutions for medical and industrial settings.…”

Effect of off-stoichiometry and Ta doping on Fe-rich (Mn,Fe)2(P,Si) based giant magnetocaloric materials

“…Different optimization strategies have been proposed to adjust the GMCE performance of (Mn,Fe) 2 (P,Si)-based MCMs like tuning the metallic (Fe-Mn) and nonmetallic (P-Si) ratios [7,8], chemical pressure engineering (substitutional/interstitial doping) including light elements doping (Li, B, C, N, F, S) [9][10][11][12], 3d transition metal doping (V, Co, Ni, Cu, Zn) [13][14][15], 4d transition metal doping (Zr, Nb, Mo, Ru) [16][17][18][19], other element doping (Al, Ge, As) [20][21][22][23] and nano-structuring [24]. Alloying with doping elements does not necessarily only tune the T tr (towards higher T tr -Li, B, C, Al, Ge, Zn and Zr; towards lower T tr -N, F, S, V, Ni, Co, Cu, Ge, Nb, Mo and Ru), but potentially also change the ΔT hys , which is detrimental to the cooling/heating efficiency [25].…”