Possible phase transition in the quasi-one-dimensional materials ZrTe5or HfTe5

The electrical resistance and static magnetic susceptibility of Zr${\mathrm{Te}}_5$, Hf${\mathrm{Te}}_5$, and some of their alloys are reported. While the resistivity shows a large peak at low temperatures, other properties do not indicate an anomaly that could be associated with a suspected phase transition. Further, a single-crystal x-ray-diffraction study failed to reveal extra diffraction peaks below room temperature that might be associated with such a transition. While it is difficult to prove the nonexistence of a phase transition, the physical properties are not similar to related materials such as Nb${\mathrm{Se}}_3$ or the transition-metal dichalcogenides which show charge-density-wave instabilities. Consequently, the resistive peak in these materials may not be due to a structural phase transition.