Data from: β-Phase Yb5Sb3Hx: Magnetic and thermoelectric properties traversing from an electride to a semiconductor

An electride is a compound that contains a localized electron in an empty
crystallographic site. This class of materials has a wide range of
applications, including superconductivity, batteries, photonics, and
catalysis. Both polymorphs of Yb5Sb3 (the orthorhombic Ca5Sb3F structure
type (β phase) and hexagonal Mn5Si3 structure type (α phase)) are known to
be electrides with electrons localized in 0D tetrahedral cavities and 1D
octahedral chains, respectively. In the case of the orthorhombic β phase,
an interstitial H can occupy the 0D tetrahedral cavity, accepting the
anionic electron that would otherwise occupy the site, providing the
formula of Yb5Sb3Hx. DFT computations show that the hexagonal structure is
energetically favored without hydrogen and that the orthorhombic structure
is more stable with hydrogen. Polycrystalline samples of orthorhombic β
phase Yb5Sb3Hx (x = 0.25, 0.50, 0.75, 1.0) were synthesized, and both PXRD
lattice parameters and 1H MAS NMR were used to characterize H composition.
Magnetic and electronic transport properties were measured to
characterize the transition from the electride (semimetal) to the
semiconductor. Magnetic susceptibility measurements indicate a magnetic
moment that can be interpreted as resulting from either the localized
antiferromagnetically coupled electride or the presence of a small amount
of Yb3+. At lower H content (x = 0.25, 0.50), a low charge carrier
mobility consistent with localized electride states is observed. In
contrast, at higher H content (x = 0.75, 1.0), a high charge carrier
mobility is consistent with free electrons in a semiconductor. All
compositions show low thermal conductivity, suggesting a potentially
promising thermoelectric material if charge carrier concentration can be
fine-tuned. This work provides an understanding of the structure and
electronic properties of the electride and semiconductor, Yb5Sb3Hx, and
opens the door to the interstitial design of electrides to tune
thermoelectric properties.