1,3-propanediammonium tetrachloromanganate(II) (NH3CH2CH2CH2NH3)MnCl4: A canted quasi-two-dimensional antiferromagnet

Abstract

The magnetic susceptibilities of single crystals of 1,3-propanediammonium tetrachloromanganate(II),(${\mathrm{NH}}_3$ ${\mathrm{CH}}_2$ ${\mathrm{CH}}_2$ ${\mathrm{CH}}_2$ ${\mathrm{NH}}_3$)Mn${\mathrm{Cl}}_4$, have been measured from 4.2 to 220°K. High-field magnetization measurements below the transition temperature are reported. In moderate magnetic fields, the material undergoes a transition to an antiferromagnetic state at $T_N=43.6\mathrm{}$°K with the $b$ axis being the preferred axis. Near-zero-field susceptibility measurements below $T_N$ reveal a more complex behavior suggestive of a canted spin system since net moments are observed along the $b$ and $c$ axes. High-field magnetization measurements along the preferred axis reveal a spin-flop transition at $H_{\mathrm{SF}}=24.2\mathrm{}$ kOe. The data below $T_N$ can be qualitatively accounted for by considering a model based on Dzyaloshinsky-Moriya interactions being included in the Hamiltonian. A plausible arrangement of the sublattice moments is suggested based on the known crystal structure. Above 50°K the susceptibilities are isotropic and reflect the quasi-two-dimensional nature of the complex. Analysis of the high-temperature series expansions reveals the intralayer exchange constant to be $\left|\frac{J}{k}\right|=4.6\mathrm{}$ K.