A Detailed IR Study of the Order-Disorder Phase Transition of AgNO3

Abstract

A complete systematic IR study (400 to 4000 cm−1) of AgNO3 is carried out over a wide range of temperature (30 to 195 °C) and new results are reported for the order–disorder phase transition II–I. The study includes measurements and interpretations of the IR spectral band shape, intensities, and frequencies of the internal modes as functions of temperature. A special attention is paid to the bending mode v2 and the combination mode (v1 + v4). The results reveal that the transformation from the order state (phase II) to the disorder state (phase I) of AgNO3 is monitored by clear variations in the spectral parameters for v2 and (v1 + v4) modes. According to the present IR analysis, the energy barrier of the reorientation of the NO 3− ions is found to be 0.25 eV in the ordered phase II and 0.14 eV in the disordered phase I. Also, the phase transition process is activated by an energy of 0.11 eV.

Relationship of photocatalysis with flavonoids in silver nanowire synthesis with herbal extract (Lavandula officinalis L.)

“…Therefore, the absence of a band around 1260 cm -1 in DS may prove that radiation-induced alkyl aryl reaction does not occur. Bands that are not observed in LE but shown at 1043 cm -1 in DS at 1039 cm -1 in LS and also around 1390 cm -1 (1378 cm -1 in LS and 1383 cm -1 in DS) show the presence of NO3 from silver nitrate [33]. The sharp band at 1383 cm -1 in DS shows the presence of more free NO3 than LS and that free Ag is more than LS, indicating that DS is more qualified in reducing silver.…”

Synchrotron X‐Ray‐Driven Nitrogen Reduction on an AgCu Thin Film

“…AgNO 3 is known to have two crystal structures, an ordered orthorhombic structure with the space group Pbca at room temperature, and a high‐temperature phase with the space group of R3cH, which is similar to the disordered high‐temperature phase of NaNO 3 . [ 25 ] A temperature‐induced phase transition occurs at about 433 K. The characteristic peaks related to AgNO 3 ‐R appeared after 10 s X‐ray irradiation and the time‐dependent variation of peak area followed a similar sigmoidal function until the 60 s, indicating that the growth of AgNO 3 ‐R also takes place on the surface of the Ag thin‐film. [ 24 ] However, the peak area of AgNO 3 ‐R decreases with an increased time after the 60 s followed by the emergence of AgNO 3 ‐P peaks, which further increased over time.…”

Calcination process and kinetic carbonation effect on the hydrated and anhydrate phases of the OPC matrix at early age of hydration

“…The variations of relaxation time (τ) and the rotational energy barrier (U) with the rate of carbonation for (a) the out-of-plane (Si-O) silicate group at ≈ 520 cm −1 , (b) the asymmetric stretching of CO 3 -mode at ≈ 1458 cm −1 , and (c) the symmetric and antisymmetric stretching (O-H) mode at ≈ 3435 cm −1 , are illustrated in Figure 5a, b, and c, respectively. The relaxation time (τ) and the rotational energy barrier (U) are obtained by the help of the following equations for the relaxation time and rotational energy barrier [29][30][31][32][33]:…”

“…where (U) is the rotational energy barrier, k is the Boltzmann , s constant, T the absolute temperature, and τ 0 = 10 −11 s [29,30]. The relaxation time (τ) and the rotational energy barrier (U) of the mode depend upon the chemical state of the vibrational group and the degree of freedom of motion due to it is position inside the sample during the kinetic carbonation process [34].…”