Re-entrant spin glass and stepped magnetization in mixed-valence SrFe3(PO4)3

Glassy magnetic ground state in layered compound MnSb2Te4

“…3c) and recent reports on few-layer MnSb 2 Te 4 [55]. Furthermore, the demagnetization steps in the Hall curves at 1.5 K are a signal of relatively complicated local magnetic structures transforming from one to another, which is distinct from those of FM metals, again confirming the glassy magnetic ground state [56][57][58]. The demagnetization steps disappear above 5 K, implying that the thermal energy could overcome the energy barrier of the transforming process, which is in good accordance with the magnetic measurements.…”

Mössbauer Spectral Study of the Low-Temperature Electronic and Magnetic Properties of α-FePO4 and the Mixed Valence Iron(II/III) Phosphate SrFe3(PO4)3

“…74, with divalent iron­(II), designated herein as Fe II , on the crystallographic Fe(2) Wyckoff 8g site with a site symmetry of .2., and with trivalent iron­(III), designated herein as Fe III , on the Fe(1) Wyckoff 4e site with a site symmetry of mm 2 . The crystal structures of a so-called “mild” 210 °C hydrothermally synthesized SrFe 3 (PO 4 ) 3 and the related BaFe 2.4 Mg 0.6 (PO 4 ) 3 and PbFe 2.4 Mg 0.6 (PO 4 ) 3 compounds, where the magnesium­(II) has replaced some of the divalent iron­(II), have been reported; the crystal structure of SrFe 3 (PO 4 ) 3 is similar to that reported earlier and the small differences probably result because the “mild” 210 °C hydrothermal synthesis is not more mild than the 375 K or 102 °C hydrothermal synthesis that was reported earlier by Korzenski et al; the so-called “mild” preparation of SrFe 3 (PO 4 ) 3 studied by Shang et al , is also in error. Unfortunately no Mössbauer spectral studies of this so-called “mild” preparation of SrFe 3 (PO 4 ) 3 have been reported.…”

Structural and Spectroscopic Studies of NaCuCr2(PO4)3: A Noncentrosymmetric Phosphate Belonging to the α-CrPO4-Type Compounds

“…They are related to the α-CrPO 4 -type structure and belong to the Na 2 O-M II O-Cr 2 O 3 -P 2 O 5 systems where M is a divalent transition-metal cation. Among other experimental results, a spin flop transition at 32 K in the NaCoCr 2 (PO 4 ) 3 compound due to the magnetic superexchange interaction competitions was reported as well as stepped magnetization in mixed-Fe 2+ /Fe 3+ phosphates. , …”

“…Among other experimental results, a spin flop transition at 32 K in the NaCoCr 2 (PO 4 ) 3 compound due to the magnetic superexchange interaction competitions was reported 10 as well as stepped magnetization in mixed-Fe 2+ /Fe 3+ phosphates. 11,12 There is a large number of compounds belonging to that high-temperature polymorph α-CrPO 4 . They are identified with the general chemical formula □ 3 M 3 (XO 4 ) 3 , where □ is a vacancy that can be filled by monovalent and/or divalent cations, introducing an oxidation state decrease of the transition metal M and XO 4 referring to tetrahedral entity, respectively.…”

“…They are identified with the general chemical formula □ 3 M 3 (XO 4 ) 3 , where □ is a vacancy that can be filled by monovalent and/or divalent cations, introducing an oxidation state decrease of the transition metal M and XO 4 referring to tetrahedral entity, respectively. They all crystallize with a centrosymmetric Imma space group. − Interestingly, some of them with the following general formula A 2 M 2+ 2 M 3+ (PO 4 ) 3 , where A is an alkali and M are metals able to show an oxidation equal to 2 and/or 3, were recently described as low-temperature polymorphs of the alluaudite-type structure. , …”