We report a systematic study of low-energy lattice vibrations in the layered systems KY(MoO), KDy(MoO), KEr(MoO), and KTm(MoO). A layered crystal structure and low symmetry of the local environment of the rare-earth ion cause the appearance of vibrational and electronic excitations in Terahertz frequencies. The interaction between these excitations leads to sophisticated dynamical properties, including non-linear effects in paramagnetic resonance spectra. The THz study in magnetic field allows for the clear distinction between lattice vibrations and electronic excitations. We measured the THz transmission spectra and show that the low energy lattice vibrations in binary molybdates can be well described within the quasi-one-dimensional model. The developed model describes the measured far-infrared spectra, and results of our calculations agree with previous Raman and ultrasound studies.

IR and far-IR reflection and absorption spectra of a layered CsDy(MoO4)2 crystal are measured in the temperature range 6–300 K. We discuss changes in the phonon spectra at the low-temperature phase transition and the characteristic vibrations, which induce a collective instability of the cooperative Jahn–Teller effect type in CsDy(MoO4)2 and other layered alkali-rare-earth molybdates. In the discussion of far-IR spectra of CsDy(MoO4)2, we use the data on RbDy(MoO4)2 obtained in the frequency range 16–40 cm−1.

The electrical resistivity and thermal conductivity as functions of temperature, for an equiatomic Fe–Ni system are studied. The samples were obtained from nickel and iron powders by a 10 min electroconsolidation at a temperature of 1100 °C, pressure 35 MPa, and current ∼5 kA, and studied in the range of 4.2–300 K. It was found that the electrical and thermal conductivity of the electroconsolidated sample is significantly higher than that of samples with the same composition, obtained by melting. It was revealed that in the investigated range of 4.2–300 K, an electroconsolidated sample’s resistivity as a function of temperature is determined by electrons scattering by defects and phonons, and the scattering of electrons by phonons can be approximated with high accuracy by the Bloch–Grüneisen–Wilson formula.