Complex magnetic phase diagram of metamagnetic MnPtSi

Abstract

The magnetic, thermal and transport properties as well as electronic band structure of MnPtSi are reported. MnPtSi is a metal that undergoes a ferromagnetic transition at TC = 340(1) K and a spin-reorientation transition at TN = 326(1) K to an antiferromagnetic phase. First-principles electronic structure calculations indicate a not-fully polarized spin state of Mn in a d 5 electron configuration with J = S = 3/2, in agreement with the saturation magnetization of 3 µB in the ordered state and the observed paramagnetic effective moment. A sizeable anomalous Hall effect in the antiferromagnetic phase alongside the computational study suggests that the antiferromagnetic structure is non-collinear. Based on thermodynamic and resistivity data we construct a magnetic phase diagram. Magnetization curves M (H) at low temperatures reveal a metamagnetic transition of spin-flop type. The spin-flopped phase terminates at a critical point with Tcr ≈ 300 K and Hcr ≈ 10 kOe, near which a peak of the magnetocaloric entropy change is observed. Using Arrott plot analysis and magnetoresistivity data we argue that the metamagnetic transition is of a firstorder type, whereas the strong field dependence of TN and the linear relationship of the TN with M 2 hint at its magnetoelastic nature.

Coexistence of magnetic order and valence fluctuations in the Kondo lattice systemCe2Rh3Sn5

“…The obtained ∆ value is comparable to those found in systems with Ce in an IV state (∆ 100 meV) 26,27,42 and is notably stronger than in other compounds from the ternary Ce-Rh-Sn system with trivalent Ce ions (∆ 80 meV) 20,[22][23][24][25] . In particular, the ∆ value for Ce 2 Rh 3 Sn 5 is larger than that for the structurally related compound CeRh 2 Sn 4 with Ce 3+ , as evidenced directly by larger intensities of f 2 satellites in the Ce 3d XPS spectra (see Fig.…”

“…We focused our search on the system Ce-Rh-Sn as it is rich in ternary phases that show a full spectrum of strongly correlated electron phenomena related to various strength of hybridization between Ce 4f and other valence band states. [20][21][22][23][24][25][26][27] CeRhSn 2 , Ce 5 Rh 4 Sn 10 , CeRh 2 Sn 4 and Ce 3 Rh 4 Sn 13 are magnetically ordered Kondo lattice systems. [20][21][22][23] In contrast, for Ce 3+x Rh 4 Sn 13−x (0.2 x 0.6) no sign of Kondo effect or long range magnetic order was found even down to 0.4 K. 25 In turn, in CeRhSn the Ce ions are in an IV state.…”

“…[20][21][22][23][24][25][26][27] CeRhSn 2 , Ce 5 Rh 4 Sn 10 , CeRh 2 Sn 4 and Ce 3 Rh 4 Sn 13 are magnetically ordered Kondo lattice systems. [20][21][22][23] In contrast, for Ce 3+x Rh 4 Sn 13−x (0.2 x 0.6) no sign of Kondo effect or long range magnetic order was found even down to 0.4 K. 25 In turn, in CeRhSn the Ce ions are in an IV state. 26,27 Here, we report on Ce 2 Rh 3 Sn 5 that crystallizes in the orthorhombic Y 2 Rh 3 Sn 5 type of structure, where Y ions occupy two distinct crystallographic sites.…”

Giant and highly anisotropic magnetocaloric effects in single crystals of disordered-perovskite RCr0.5Fe0.5O3 (R = Gd, Er)

“…As shown in Fig. 3 , we constructed the Belov-Arrott plot to determine the order of magnetic phase transition at T SR,1 ≈ 180 K. The slope was found to be positive for the overall regime of spin-reorientation, which suggests a second-order phase transition 44 , 45 . However, EFCO also exhibits signatures of a first-order phase transition such as thermally hysteretic behavior between ZFC and FC data (Fig.…”

Strong magnetoelastic coupling in MnCoSi compounds studied in pulsed magnetic fields

“…According to the Debye model [54], the specific heat C p versus temperature shows a maximum slope around 0.28θ D , where θ D is the Debye temperature [54,55]. For MnCoSi and related derivatives θ D is between 375 and 385 K [56,57], resulting in a maximum slope around 100 K. For temperatures below 0.1θ D (about 40 K), the amount of thermally excited phonons is very low, which is consistent with our experimental observation (no transition).…”