Magnetic hyperfine field splitting in the Zintl phase Eu${}_2$Mg${}_4$Si${}_3$

Eu${}_2$Mg${}_4$Si${}_3$ $\equiv$ (2Eu${}^{2+}$)(4Mg${}^{2+}$)(3Si${}^{4-}$) is an electron-precise Zintl phase. Its Hf${}_2$Co${}_4$P${}_3$-type structure contains three crystallographically independent europium sites. The divalent state of europium was manifested through ${}^{151}$Eu Mössbauer spectroscopy. In the paramagnetic regime (T = 78 K) the isomer shifts range from −9.16 to −11.29 mm s${}^{-1}$. Eu${}_2$Mg${}_4$Si${}_3$ shows complex magnetic hyperfine field splitting at T = 5.7 K with a superposition of three subspectra with magnetic hyperfine fields of 5.4 (Eu2), 20.4 (Eu1) and 22.4 (Eu3) T.