Sliding twin-domains in self-heated needle-like VO single crystals.

The prototypical metal-insulator transition in VO at 340 K is from a high-temperature rutile phase to a low-temperature monoclinic phase. The lower symmetry of the monoclinic structure removes the degeneracy of the two equivalent directions of the tetragonal structure, giving rise to twin domains. Since formation of domain walls require energy most needle-like monoclinic single crystal are single-domain.

Switching VO₂ Single Crystals and Related Phenomena: Sliding Domains and Crack Formation.

VO₂ is the prototype material for insulator-metal transition (IMT). Its transition at T = 340 K is fast and consists of a large resistance jump (up to approximately five orders of magnitude), a large change in its optical properties in the visible range, and symmetry change from monoclinic to tetragonal (expansion by 1% along the tetragonal -axis and 0.5% contraction in the perpendicular direction).

The absence of charge-density-wave sliding in epitaxial charge-ordered Pr(0.48)Ca(0.52)MnO(3) films.

For an epitaxial Pr(0.48)Ca(0.52)MnO(3) film on NdGaO(3), we use transmission electron microscopy to observe a 'charge-ordered' superlattice along the in-plane direction a.

Muon spin relaxation measurements of NaxCoO2.yH2O.

Using the transverse field muon spin relaxation technique, we measure the temperature dependence of the magnetic field penetration depth lambda, in the NaxCoO2.yH(2)O system. We find that lambda, which is determined by the superfluid density n(s) and the effective mass m*, is very small and on the edge of the TF-microSR sensitivity.