Zero-field splitting in tetragonal di-iodotetrakis(pyrazole)-manganese(II)

Abstract

The sign and magnitude of the zero-field splitting in trans-di-iodotetrakis(pyrazole)manganese(II), Mn(pz)₄I₂, has been determined with the aid of e.p.r. powder spectra, heat capacity measurements from 1.3–80 K, paramagnetic susceptibility measurements from 2–80 K, and isothermal magnetization at 2–20 K. The results of all types of measurements are consistent with an axial splitting parameter of the d⁵ Mn^II ion, D, of 0.98 ± 0.02 cm^–1, which means that the m_s=±½ doublet lies lowest with higher states at 2D and 6D. The value of E(the rhombic splitting parameter) was found to be less than 0.01 cm^–1.

No co-operative ordering has been observed down to 1.3 K.