On the character of the scattering of wide-band x-ray radiation in the low-temperature phase of 2 H ‐ Nb Se 2

The intensity of x-ray scattering in the layered metal 2 H ‐ Nb Se 2 has been investigated experimentally in the temperature range below the temperature of the transition into the charge-density wave state. It is shown that the relation I ∼ ( T C − T ) − γ with T C ∼ 30 K and γ = 1.6 ± 0.2 , as is characteristic for quasi-elastic (quasi-Bragg) scattering, describes the scattering intensity. Such scattering is strong when the width Δ ε XR of the spectral distribution of the x-ray radiation is greater than the spectral width of the fluctuations Δ ε f of the order parameter. The inequality Δ ε f < Δ ε f holds for scattering of slow neutrons, for which quasi-elastic scattering is immeasurably weak.