of Yb14–xLuxZnSb11 (x = 0.3) were performed
on pieces of dense pellets using
thermogravimetry and differential scanning calorimetry (TG/DSC, Netzsch
STA 449 Jupiter) under a 50 mL/min flow of dry air (20% oxygen in
N2, Praxair) in Al2O3 crucibles from
room temperature to 1000 °C. To investigate the oxidation reaction
on a larger scale, a pellet of x = 0.3 was prepared
and after confirmation of purity by PXRD, the pellet was polished
and put in a box furnace in an Al2O3 holder.
It was heated at 200 °C/h to 1000 °C and held at that temperature
for 12 h in an ambient atmosphere. Half of this oxidized pellet was
set in epoxy for SEM imaging of the cross-section. The other half
was taken apart, the individual components were ground, and the PXRD
was collected and analyzed.