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The binary manganese–rhodium (Mn–Rh) phase diagram was reinvestigated from 5 to 90 at.% Rh with focus on determining the transition temperature between the ordered γ′-Mn3Rh and the γ-Mn phase as well as the transition temperature between of the tetragonal and cubic MnRh phase and phase boundaries, applying XRD, DTA and SEM including EDX. A reassessment of the Mn–Rh phase diagram based on obtained and literature data is given. Furthermore, the phase equilibria of the ternary bismuth–manganese–rhodium (Bi–Mn–Rh) system were experimentally investigated, focusing on the possible existence of new ferromagnetic phases. Isothermal sections at 330 °C and 600 °C were studied applying powder XRD and EDX. The corresponding phase diagram was established based on these results. No additional ferromagnetic phase was found in the ternary system. [ABSTRACT FROM AUTHOR]

The phase equilibria of the ternary system Bi-Mn-Sb were experimentally investigated with focus on the possible existence of a ferromagnetic continuous solid solution between α-BiMn and MnSb at 320 °C (both B81, NiAs structure type). Isothermal sections at 320 and 600 °C were studied applying powder x-ray diffraction and scanning electron microscopy including energy dispersive x-ray spectroscopy. The corresponding isothermal sections at 320 and 600 °C were established based on these results. A complete ternary reaction scheme (Scheil diagram) and a liquidus surface projection based on primary crystallization analyses and DTA (differential thermal analysis) were constructed. Furthermore, the vertical section at 10 at.% Sb was studied by DTA. A continuous solid solution between the isostructural phases α-BiMn and MnSb, as reported in the literature, could not be confirmed. A new hexagonal P63/mmc setting of the known orthorhombic P2221 ternary phase BixMnSb1−x, based on single-crystal x-ray diffraction data, is described. [ABSTRACT FROM AUTHOR]

A study of the ternary Rh–Mn–Bi phase diagram revealed the existence of two new ternary bismuthides, viz. hexarhodium pentamanganese octadecabismuthide (Rh6Mn5Bi18) and rhodium manganese tribismuthide (RhMnBi3). Their crystal structures represent new structure types. Rh6Mn5Bi18, with a Wyckoff sequence af2 g2 i5, crystallizes in the tetragonal system (space group P42/mnm; Pearson symbol tP58), and RhMnBi3, with a Wyckoff sequence a c g i q, crystallizes in the orthorhombic system (Cmmm; oS20). In the Rh6Mn5Bi18 structure, the transition metal atoms are linked into ribbon‐like structural units aligned along the [001] direction, whereas planar sheets are formed in RhMnBi3. In both crystal structures, the units formed by the transition metal atoms are enveloped by Bi atoms, which themselves form a loosely bound network. The linkage results in a layer structure for RhMnBi3, while in the case of Rh6Mn5Bi18, a three‐dimensional network is formed; the latter, however, contains several areas where Bi…Bi distances suggest van der Waals interactions. Both phases under discussion have analogous structural motifs. [ABSTRACT FROM AUTHOR]

The binary bismuth-rhodium (Bi-Rh) phase diagram was reinvestigated from 23 to 60 at.% Rh with focus on the BiRh phase, applying powder-x-ray diffraction (XRD), high temperature powder-XRD, differential thermal analyses and scanning electron microscopy. The phase boundaries of the BiRh phase at 750 °C and the temperature of its peritectic decomposition were refined. In addition, the existence of the two phases BiRh and BiRh (in two modifications depending on temperature) could be confirmed. Most of the reaction temperatures reported in the literature could be verified within a range of about ± 10 °C. Nevertheless, a few temperatures had to be revised, such as those of the peritectic reactions L + Rh $$\rightleftharpoons$$ BiRh at 979 °C and L + BiRh $$\rightleftharpoons$$ β-BiRh at 785 °C. No evidence could be found for the presence of a stable BiRh phase in well annealed samples; from the present results it must be concluded that BiRh is actually metastable. On the other hand, a new orthorhombic phase BiRh was discovered which crystallizes in the MnP structure type (Pmna). It was found that the temperatures of the transition between the low-temperature modification α-BiRh and its high-temperature form β-BiRh depend considerably on the presence or absence of metastable BiRh and stable BiRh, respectively. [ABSTRACT FROM AUTHOR]

The binary manganese-antimony (Mn-Sb) phase diagram was reinvestigated in the whole composition range using powder-XRD, DTA and SEM-EDX. The phase boundaries and melting temperatures of the ferromagnetic phases MnSb and MnSb were modified by taking into account the new experimental data. Most of the reaction temperatures could be verified within a range of ±10 °C. Nevertheless, a few temperatures had to be revised, such as the eutectic reaction L → β- Mn + Mn Sb at 893 °C and the eutectoid reaction β- Mn → α- Mn + Mn Sb at 718 °C. The previously reported peritectic melting behavior of MnSb could be confirmed. The variation of the lattice parameters of the NiAs-( B8 ) type MnSb phase with composition was determined. A revised version of the of the Mn-Sb phase diagram is presented. [ABSTRACT FROM AUTHOR]