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Abstract Single crystals of disordered Mn_4–xCr_xAl₁₁have been synthesized via the flux method. EDS on several crystals of various sizes and shapes revealed an average molar ratio of 17:9:74 for Mn:Cr:Al, while X-ray diffraction on three different crystals yield compositions Mn_2.26Cr_1.74Al₁₁(Mn_4–xCr_xAl₁₁,x= 1.74), Mn_0.83Cr_3.17Al₁₁, and Mn_1.07Cr_2.93Al₁₁. This compound crystallizes in space groupP–1, isostructural with both Mn₄Al₁₁and Cr₄Al₁₁. Magnetic measurements on several crystals show that this disordered compound is ferrimagnetic with a low effective moment ofμ_eff≈1.012±0.004 μ_B/f.u. and a non-reachable transition temperature. DFT calculations display opening of a bandgap in the spin-up channel near the Fermi level with increasing Cr content, an indication of half-metallicity. 

Abstract A new cage-structured compound—HfMn₂Zn₂₀—belonging to theAB₂C₂₀ (A, B= transition or rare earth metals, andC= Al, Zn, or Cd) family of structures has been synthesized via the self-flux method. The new compound crystallizes in the space group $Fd\overline{3}m$ with lattice parameter a≈14.0543(2) Å (Z= 8) and exhibits non-stoichiometry due to Mn/Zn mixing on the Mn-site and an underoccupied Hf-site. The structure refines to Hf_0.93Mn_1.63Zn_20.37and follows lattice size trends when compared to other HfM₂Zn₂₀(M= Fe, Co, and Ni) structures. The magnetic measurements show that this compound displays a modified Curie-Weiss behavior with a transition temperature around 22 K. The magnetization shows no saturation, a small magnetic moment, and near negligible hysteresis, all signs of itinerant magnetism. The Rhodes–Wohlfarth ratio and the spin fluctuation parameters ratio both confirm the itinerant nature of the magnetism in HfMn₂Zn₂₀. 

The organic metal halide hybrids welcome a new member with a one-dimensional (1D) tubular structure. Herein we report the synthesis and characterization of a single crystalline bulk assembly of organic metal halide nanotubes, (C 6 H 13 N 4 ) 3 Pb 2 Br 7 . In a metal halide nanotube, six face-sharing metal halide dimers (Pb 2 Br 9 5− ) connect at the corners to form rings that extend in one dimension, of which the inside and outside surfaces are coated with protonated hexamethylenetetramine (HMTA) cations (C 6 H 13 N 4 + ). This unique 1D tubular structure possesses highly localized electronic states with strong quantum confinement, resulting in the formation of self-trapped excitons that give strongly Stokes shifted broadband yellowish-white emission with a photoluminescence quantum efficiency (PLQE) of ∼7%. Having realized single crystalline bulk assemblies of two-dimensional (2D) wells, 1D wires, and now 1D tubes using organic metal halide hybrids, our work significantly advances the research on bulk assemblies of quantum-confined materials.