The structural, thermodynamic, and magnetic properties of Na₂CrCl₄ have been investigated to provide fundamental insights into this ternary halide relevant to chloride-based molten salt reactor systems. Room-temperature powder X-ray and neutron diffraction confirm a monoclinic (P2₁/c) structure and phase purity. Neutron diffraction measurements at 4.6 K reveal additional magnetic reflections indexed with (Formula presented), indicating the onset of long-range antiferromagnetic order. Low-temperature heat capacity measurements in the range 2–300 K show a pronounced λ-type anomaly at T_N = 8.5 ± 0.5 K, with an associated magnetic entropy S_mag = 11.9 ± 0.4 J K^–1 mol ^–1 consistent with antiferromagnetic ordering of high-spin Cr²⁺ (S = 2), a second-order phase transition. The standard molar entropy at 298.15 K, S_m^°(298.15 K) = 256.8 ± 7.7 J K^–1 mol ^–1, is slightly lower than previous CALPHAD assessments of the NaCl-CrCl₂ system. Magnetic susceptibility measurements also confirm antiferromagnetic behavior, with a Curie–Weiss fit giving μ_eff = 5.57 ± 0.05 μ_B and θ_CW = −15.0 ± 1.0 K. Compared to the related ferromagnetic chlorides K₂CrCl₄, Rb₂CrCl₄, and Cs₂CrCl₄, Na₂CrCl₄ exhibits a distinctly lower ordering temperature and antiferromagnetic structure, likely due to variations in lattice geometry and exchange interactions. These results provide the first experimental thermodynamic parameters for Na₂CrCl₄, contributing to refining phase diagrams and corrosion models in chloride salt systems.

The detailed crystal structure as well as the heat capacity at low temperature and standard entropy of Ba2MoO5 are reported for the first time. High-resolution X-ray and neutron diffraction were employed to reveal the structural features of this compound. Ba2MoO5 has a six-coordinated Mo and a strongly negative excess volume with respect to the binary oxides. X-ray absorption near edge structure (XANES) spectroscopy at the Mo K-edge shows Mo to be in the oxidation state 6+. The pre-edge peak in the XANES spectrum indicates a distorted octahedral environment, in line with the results from diffraction studies and FDMNES calculations. The standard entropy and heat capacity of Ba2MoO5 at 298.15 K, determined with a thermal-relaxation technique, are calculated to be respectively 223.2 ± 7 and 184.7 ± 5 J·K–1·mol–1. The obtained thermodynamic properties are discussed in the context of the literature reports on molybdate compounds.

This work presents two color LIF temperature measurements for the transient freezing in a square channel under laminar flow conditions. This is the first time non-intrusive temperature measurements were performed within the thermal boundary layer during the transient growth of an ice layer in internal flow. A combination of a local outlier factor algorithm and a smoothing operation was used to remove the top to bottom striations and reduce the other measurement noise. The temperature uncertainty in our measurements was between σ=0.3∘C and σ=0.5∘C. For the largest temperature difference between the bulk and the melting point of 14.6 °C, good results were obtained. As such, the current campaign demonstrates the potential of LIF as a non-intrusive temperature measurement technique for solid–liquid phase change experiments. However, some artefacts were present within the vicinity of the ice-layer due to the scattering of the laser light, especially near the inlet of the channel where the ice-layer is curved instead of flat. LIF measurements taken within a short time span prior to the onset of ice freezing showed approximately 2 °C of subcooling, consistent with previous findings. In addition, an anomalous behavior within the thermal boundary layer was observed, with a much smaller temperature gradient within the first few mm above the cold plate and a point of inflection in the temperature profile. The anomalous temperature behavior is possibly attributed to enhanced natural convection as a result of the subcooling at the cold plate surface.

A combined experimental and modelling study into the Pb-Mo-O system has been conducted in view of the safety analysis for lead-cooled nuclear systems. The thermal expansion and low-temperature heat capacity of the ternary compounds PbMoO4 and Pb2MoO5 have been determined experimentally, as well as the melting enthalpy of PbMoO4. Moreover, XANES measurements have confirmed the hexavalent oxidation state of Mo in PbMoO4 and Pb2MoO5.

A thermodynamic model of the ternary system including the ternary phases PbMoO4, Pb2MoO5 and Pb5MoO8 has also been developed in this work based on the CALPHAD methodology. For the first time, an ionic two-sublattice model is used for the liquid phase, while the compound energy formalism is used for the solid phases.