EuNi₂P₄, the first magnetic unconventional clathrate preparedviaa mechanochemically assisted route

Abstract

The first magnetic unconventional clathrate EuNi2P4 has been prepared and its thermodynamic properties have been investigated.

Chemically driven superstructural ordering leading to giant unit cells in unconventional clathrates Cs8Zn18Sb28 and Cs8Cd18Sb28

“…and group 15 pnictogen elements (P, As, or Sb), such as Ba 8 Cu 16 P 30 , EuNi 2 P 4 , or SrNi 2 P 4 . [4][5][6][7][8] For unconventional clathrates, superstructural ordering of the framework and guest positions is common. For example, Ba 8 M 16 P 30 (M ¼ Cu, Au) clathrates exhibit superstructural order of their framework, in which M and P segregate into distinct sites.…”

Clathrate BaNi2P4: An Interplay of Heat and Charge Transport Due to Strong Host–Guest Interactions

“…guests have been reported, [7,8] whereas larger Eu 2+ guests are more common. [9][10][11][12] In unconventional clathrates, the framework is based on a late-or post-transition metal and a pnictogen, group 15 element (P, As, and Sb). [4] Unconventional clathrates can be tuned to be semiconductors with outstanding charge transport properties.…”

“…In conventional clathrates, the frameworks are based on group 14 elementsSi, Ge, and Sn. Many conventional clathrates are semiconductors and can be applied in the fields of thermoelectrics, photovoltaics, electrochemical energy storage, and gas storage. , A small subset of Ba–Si clathrates with metallic properties exhibit superconductivity due to unique host–guest interactions, namely hybridization of Ba 5d and Si 3p orbitals. , Exciting physical properties have been predicted for metallic clathrates containing rare-earth guests with partially filled f-shells, but due to the small size of rare-earth cations, only two reliable examples of Ce 3+ guests have been reported, , whereas larger Eu 2+ guests are more common. − In unconventional clathrates, the framework is based on a late- or post-transition metal and a pnictogen, group 15 element (P, As, and Sb) . Unconventional clathrates can be tuned to be semiconductors with outstanding charge transport properties. ,, The metallic unconventional clathrate BaNi 2 P 4 attracted our attention due to an observed inconsistency in the thermal and electrical conductivities measured on sintered polycrystalline samples, indicating a possible violation of the Wiedemann–Franz (WF) law κ E = LT /ρ, where κ E is the electronic contribution to the total thermal conductivity, ρ is the electrical resistivity, L is the Lorentz number, and T is the absolute temperature.…”

Metal-Rich Phosphides Obtained from the Lead Flux: Synthesis, Crystal, and Electronic Structure of Sr5Pt12P9 and BaPt3P2

“…The order of the distances from the cation to the framework, as well as a general structure motif, where Pt and P form 3D frameworks with rather large cages, might be seen as relating the structures of Sr 5 Pt 12 P 9 and BaPt 3 P 2 to certain unconventional clathrates . However, the polyhedra in both our compounds are less regular and cages more distorted than, for example, in unconventional clathrates such as AEM 2 P 4 (AE = Sr., Ba; M = Ni, Cu, Pd) − or EuNi 2 P 4 …”

“…BaPd 2 P 4 and β-BaNi 2 P 4 compounds crystallize in their own structure types, and another modification α-BaNi 2 P 4 is isotypic with BaPd 2 P 4 . EuNi 2 P 4 is isotypic with SrNi 2 P 4 , which forms its own structure type and belongs to twisted clatrates. The BaAu 3 Ge structure type, in addition to the SrPt 3 P mentioned above, also includes CaPt 3 P and EuPt 3 P, and the SrPt 6 P 2 structure type also includes its analogue with europium EuPt 6 P 2 .…”