STRUCTURAL MODULATIONS IN UPT3, SINGLE-CRYSTAL WHISKERS

Recent transmission electron microscopy (TEM) data on the heavy fermio n superconductor UPt3 find a complex periodic modulation in the basal plane, the nature of which is unclear. We present TEM data on single c rystal whiskers of UPt, grown spontaneously from the melt. We find a m odulation in the a-e plane, consistent with a description in terms of a single q, allowing us to present the first accurate determination of the c() component of the modulation. This structure persists across a wide area of the whisker, making these samples candidates for X-ray studies of the modulation.