  We performed polarized Raman spectroscopy on mechanically exfoliated
few-layer MoTe2 samples and observed both 1T' and Td phases at room
temperature. Few-layer 1T' and Td MoTe2 exhibited a significant difference
especially in interlayer vibration modes, from which the interlayer coupling
strengths were extracted using the linear chain model: strong in-plane
anisotropy was observed in both phases. Furthermore, temperature-dependent
Raman measurements revealed a peculiar phase transition behavior in few-layer
1T' MoTe2. In contrast to bulk 1T' MoTe2 crystals where the phase transition to
the Td phase occurs at ~250 K, the temperature-driven phase transition to the
Td phase is increasingly suppressed as the thickness is reduced, and the
transition and the critical temperature varied dramatically from sample to
sample even for the same thickness. Raman spectra of intermediate phases that
correspond to neither 1T' nor Td phase with different interlayer vibration
modes were observed, which suggests that several metastable phases exist with
similar total energies.
