A Ferrimagnetic Zintl Phase Pr₄MnSb₉: Synthesis, Structure, and Physical Properties

Abstract

A new valence precise Zintl phase, Pr₄MnSb₉, has been successfully synthesized by solid-state reaction at high temperature. The single-crystal X-ray diffraction data reveal its monoclinic symmetry in the space group <i>C</i>2/<i>m</i> (No. 12) with <i>a</i> = 24.12(2) Å, <i>b</i> = 4.203(3) Å, <i>c</i> = 15.67(2) Å, β = 98.05(1)°, and <i>Z</i> = 4. The structure is characterized by the covalent three-dimensional network constructed by two types of five-atom-wide Sb₅^7– ribbons that are joined by 6-fold coordinated Mn³⁺ cations, through which the narrower three-atom-wide Sb₃^5– ribbons are attached as a tag, and interstitial Pr³⁺ cations and single Sb^3– anions locate within the tunnels. Its magnetic susceptibility and isothermal hysteresis suggest ferrimagnetic behavior. The electrical conductivity and Seebeck coefficient of the cold-pressed pellet suggest a semimetal feature that agrees with the spin-polarized calculation results using the tight-binding linear muffin-tin orbital (TB-LMTO) method