Field dependence of magnetic entropy change in Mn5Ge3 near room temperature

Unraveling the magnetic properties and nature of exchange interactions of Mn5−x Fe x Ge3 (0.15 ≤ x ≤ 0.5) alloys

“…The Curie temperature (T C ) corresponding to PM → FM magnetic transition is 304 K, 308 K and 316 K for x = 0.15, 0.3 and 0.5, respectively (calculated from the dM/dT curves [See inset of figures 2(a)-(c)]). It is worth mentioning that with increasing Fe content in Mn 5 Ge 3 , a linear enhancement from T C from 297 K for pure Mn 5 Ge 3 [3] to 316 K was observed as shown in the inset of figure 3 for Mn 4.5 Fe 0.5 Ge 3 alloy. This can be easily understood in terms of enhancement of FM exchange interactions between Mn 1 -Fe, Mn 2 -Fe and Fe-Fe on account of Fe doping [11,19].…”

“…The study of critical phenomena is known to be a powerful tool to probe the relevant microscopic interactions responsible for the magnetic properties and provide insights into the (i) effective Hamiltonian driving the magnetism; (ii) dimensionality of the system; (iii) the range of the spinspin interactions. Our previous study revealed that the critical exponents of polycrystalline Mn 5 Ge 3 [3] alloy follow 3D Ising (anisotropic) universality class whereas melt-spun Mn 4 FeGe 3 ribbons [17] with similar crystal structure follow 3D Heisenberg (isotropic) model. It would be interesting to probe the intermediate compositions to ascertain whether Fe doping in place of Mn could give rise to a transition from one universality class to another in Mn 5 Ge 3 alloy.…”

“…The Mn-based intermetallic Mn 5 Ge 3 [1] with hexagonal Mn 5 Si 3 -type structure (space group P6 3 /mmc) has been receiving considerable attention over the last few decades due to its weak itinerant ferromagnetism, near room-temperature magnetocaloric properties [2,3] (DS m max ;5-9 J/kg-K, RC ;400 J kg −1 at 5 T), reasonable spin polarization [4] (≈40%) and being a viable candidate for spin injector candidates in spintronics devices [5].…”

Chiral-fluctuations mediated helical to paramagnetic phase transition and scaling study in β-Mn type Co8Zn8Mn4 chiral magnet

“…Further, an iterative self-consistent method [32] was performed by rescaling the M(H) isotherm with the initial critical exponents of the 3D Heisenberg universality class (β = 0.365 and γ = 1.386). The M S (T) and 1/χ 0 (T) obtained from highfield linear extrapolation of MAPs below and above T C , are fitted to equations ( 3) and ( 4), respectively which give a new set of exponent values for the next iteration.…”

Critical behavior in the Mn$_{5}$Ge$_{3}$ ferromagnet

“…In addition, it is believed that the coexistence of AFM and FM coupling observed at low temperature may lead to the low-temperature noncollinear spin configuration which is commonly observed in Mn 5 Ge 3 thin film or nanowire [20,22,23,27]. Mn 5 Ge 3 has been widely studied for its magnetocaloric properties due to the large effect near room temperature, which makes it a potential candidate for magnetic refrigeration with the advantage of being environment friendly [28][29][30][31]. Though the magnetothermal properties of Mn 5 Ge 3 have been extensively investigated, further studies are desired to understand the intrinsic magnetic interactions, especially the critical behavior in Mn 5 Ge 3 single crystal.…”