CsMn₄As₃: A Layered Tetragonal Transition-Metal Pnictide Compound with an Antiferromagnetic Ground State

Abstract

We report the synthesis and properties of a new layered tetragonal ternary compound CsMnAs (structure type, KCuS; space group, P4/ mmm, no. 123; and Z = 2). The material is a small band gap semiconductor and exhibits an antiferromagnetic ground state associated with Mn spins. The compound exhibits a signature of a distinct magnetic moment canting event at 150(5) K with a canting angle ≈ 0.3°. Although some features of the magnetic characteristics of this new compound are qualitatively similar to those of the related BaMnAs, the underlying Mn sublattices of the two materials are quite different. While the Mn square-lattice layers in BaMnAs are equally spaced along the c-direction with the interlayer distance d = 6.7341(4) Å, the Mn sublattice forms bilayers in CsMnAs with the interlayer distance within a bilayer being d = 3.1661(6) Å; the distance between the two adjacent bilayers is d = 7.290(6) Å. This difference in the Mn sublattice is bound to significantly alter the energy balance among the J, J, and J exchange interactions within the J- J- J model compared to those in BaMnAs and the other related 122 compounds, including the well-known iron-arsenide superconductor parent compound BaFeAs. Owing to the novelty of its transition-metal sublattice, this new addition to the family of tetragonal materials related to the iron-based superconductors brings prospects for doping and pressure studies in the search of new superconducting phases as well as other exciting correlated electron properties.

Instability and evolution of the magnetic ground state in metallic perovskitesGdRh3C1−xBx

“…The high-temperature (T > T H ) C p (T ) data could not be fitted satisfactorily using solely the Debye model of acoustic phonons, as shown in Supplemental Fig. S5 [30], but the fit improved significantly by employing the single-frequency Einstein term [30] along with the Debye model [39] (Fig. 4, left panels).…”

Instability and evolution of the magnetic ground state in metallic perovskites GdRh$_3$C$_{1-x}$B$_x$

“…The high-temperature (T > T H ) C p (T ) data could not be fitted satisfactorily using solely the Debye model of acoustic phonons (Fig. S3, Supplementary Material), but the fit improved significantly by employing the single-frequency Einstein term along with the Debye model [36] (left panels, Fig. 4).…”

Ternary ACd4P3 (A = Na, K) Nanostructures via a Hydride Solution-Phase Route

“…KMn 4 As 3 ), tetragonal P4/ mmm (KCu 4 S 3 -type, includes (K/Rb/Cs)Zn 4 As 3 , Cs(Cd/ Mn) 4 As 3 , and RbMn 4 As 3 ), or rhombohedral R3̅ m (NaZn 4 As 3 and (Na/K/Rb)Cd 4 As 3 ) structures, and are studied for their magnetic and thermoelectric behavior. 16,19,20 Interestingly, NaCd 4 P 3 undergoes a phase transition from R3̅ m to a modulated Cm(α0γ)s structure at ∼260 K. 18 With such rich structural diversity and competing binary phases, it can be challenging to synthesize these materials in a phase-pure manner.…”

“…Pnictide compounds continue to attract significant attention because of their rich structural chemistry and because of their unique optoelectronic and catalytic properties. − Binary pnictides adopt a variety of structures with complex pnictogen motifs including tubular fragments, layers, clusters, and cages . Heavily studied ternary pnictide phases include those from the CaAl 2 Si 2 and ThCr 2 Si 2 type structures that exhibit potential in superconductivity, − thermoelectric, ,,− and optical applications. , Recently reported I–II 4 –V 3 compounds (I = alkali metal; II = divalent transition metal; V = pnictide) adopt a variety of related crystal structures (Figure ), all of which share structural similarities to CaAl 2 Si 2 and ThCr 2 Si 2 type structures. − These Zintl phases comprise edge- and corner-sharing II–V 4 tetrahedra making up polyanionic layers. The polyanionic layers are charge-balanced by intercalated I + cations (I = Na, K, Rb, or Cs).…”

“…I–II 4 –As 3 phases adopt orthorhombic Pnma (CaFe 4 As 3 -type structure, e.g. KMn 4 As 3 ), tetragonal P 4/ mmm (KCu 4 S 3 -type, includes (K/Rb/Cs)­Zn 4 As 3 , Cs­(Cd/Mn) 4 As 3 , and RbMn 4 As 3 ), or rhombohedral R 3̅ m (NaZn 4 As 3 and (Na/K/Rb)­Cd 4 As 3 ) structures, and are studied for their magnetic and thermoelectric behavior. ,, …”