Investigation of Fe incorporation in LnCr2Al20 (Ln = La, Gd, Yb) with 57Fe Mössbauer and single crystal X-ray diffraction.

ABSTRACT

Crystal growth, structure determination, and magnetic properties of LnCr2Al(20-x)Fe(x) (Ln = La, Gd, Yb) adopting the CeCr2Al20 structure type with space group Fd3m, a ∼ 14.5 Å, are reported. Single crystal X-ray diffraction and Mössbauer spectroscopy are employed to fully characterize the crystal structure of LnCr2Al(20-x)Fe(x) (Ln = La, Gd, Yb). LnCr2Al(20-x)Fe(x) (Ln = La, Gd, Yb) are the first pseudoternaries adopting the CeCr2Al20 structure type with a transition metal occupying the main group site. The Yb analogues are Pauli paramagnets with the Yb ion adopting an electronic configuration close to Yb(2+), while the Gd analogues show paramagnetic behavior with no magnetic order down to 3 K.