XMCD characterization of the ferromagnetic state of Yb14MnSb11

X-ray magnetic circular dichroism (XMCD) measurements on Yb14MnSb11 provide experimental evidence of a moment of 5 mu(B) on Mn, with partial cancellation by an opposing moment on the Sb-4 cage surrounding each Mn ion. The compound is isostructural to Ca14AlSb11, with Mn occupying the Al site in the AlSb49- discrete tetrahedral, anionic unit. Bulk magnetization measurements indicate a saturation moment of 3.90 +/- 0.02 mu(B)/formula unit consistent with four unpaired spins and implying a Mn3+, high-spin d(4) state. XMCD measurements reveal that there is strong dichroism in the Mn L-23 edge, the Sb M-45 edge shows a weak dichroism indicating antialignment to the Mn, and the Yb N-45 edge shows no dichroism. Comparisons of the Mn spectra with theoretical models for Mn 21 show excellent agreement. The bulk magnetization can be understood as Mn with a moment of 5 mu(B) and a 2+ configuration, with cancellation of one spin by an antialigned moment from the Sb 5p band of the Sb-4 cage surrounding the Mn.