The current status of theoretical studies on the quantum chromodynamics (QCD) phase diagram at finite temperature and baryon chemical potential is reviewed with special emphasis on the origin of various phases and their symmetry breaking patterns. Topics include quark deconfinement, chiral symmetry restoration, order of the phase transitions, QCD critical point(s), colour superconductivity, various inhomogeneous states and implications from QCD-like theories.

https://iopscience.iop.org/article/10.1088/0034-4885/74/1/014001/pdf

The phase diagram of dense QCD

https://dr.ntu.edu.sg/bitstream/10356/101824/1/A%20comprehensive%20review%20on%20the%20progress%20of%20lead%20zirconate-based%20antiferroelectric%20materials.pdf

A comprehensive review on the progress of lead zirconate-based antiferroelectric materials

Perovskite-type SrZrO3 was investigated as an alternative to yttria-stabilized zirconia (YSZ) material for thermal barrier coating (TBC) applications. Three phase transformations (orthorhombic↔pseudo-tetragonal↔tetragonal↔cubic) were found only by heat capacity measurement, whereas the phase transformation from orthorhombic to pseudo-tetragonal was found in thermal expansion measurements. The thermal expansion coefficients (TECs) of SrZrO3 coatings were at least 4.5% larger than YSZ coatings up to 1200°C. Mechanical properties (Young's modulus, hardness, and fracture toughness) of dense SrZrO3 showed lower Young's modulus, hardness, and comparable fracture toughness with respect to YSZ. The “steady-state” sintering rate of a SrZrO3 coating at 1200°C was 1.04 × 10−9 s−1, which was less than half that of YSZ coating at 1200°C. Plasma-sprayed coatings were produced and characterized. Thermal cycling with a gas burner showed that at operating temperatures ∼1250°C the cycling lifetime of SrZrO3/YSZ double-layer coating (DLC) was more than twice as long as SrZrO3 coating and comparable to YSZ coating. However, at operating temperatures >1300°C, the cycling lifetime of SrZrO3/YSZ DLC was comparable to the optimized YSZ coating, indicating SrZrO3 might be a promising material for TBC applications at higher temperatures compared with YSZ.

Perovskite-Type Strontium Zirconate as a New Material for Thermal Barrier Coatings

Hidden nature of the high-temperature phase transitions in crystals of KH2PO4-TYPE : Is it a physical change ?

Impedance spectroscopy and dielectric analysis in KH2PO4 single crystal

The high‐temperature phase transition in KH2PO4 has been investigated by differential thermal analysis, thermogravimetric analysis, proton magnetic resonance and relaxation, infrared spectroscopy, and x‐ray and quasielastic cold‐neutron scattering. The transition is not connected with a static breaking up of the hydrogen‐bond network but rather with the onset of disordered hindered rotation of the H2PO4 groups around all three axes. It seems that rotation of H2PO4 groups is as well rate determining for the proton conductivity of this crystal.

D. Hadži

Papers

High‐Temperature Phase Transition in KH2PO4