Overview of structural, electronic, elastic, thermal, optical, and nuclear properties of Zr2AC (A= Al, Si, P, S, Ge, As, Se In, Sn, Tl, and Pb) MAX phases: A brief review.

The Zr2AC MAX phases are a family of ternary carbides ceramics that possess layered structures and exhibiting exceptional properties resulting from combining the most desirable features of metals and ceramics. In addition, the Zr2AC MAX-phases exhibit numerous physical and chemical properties due to their chemical and structural characteristics, a tendency for multiple basal dislocations and exhibiting mobility under ambient conditions. This review extensively analyzes the properties of the Zr2AC MAX phase, as they are closely linked to the exceptional and potential applications of the MAX phase. For the first time, the present study analyzed various properties of Zr2AC MAX phases, including structural, electronic, elastic, thermal, optical, self-healing, nuclear, oxidation, and corrosion characteristics. Furthermore, this review included experimental and theoretical work with comparison. It's found that the Zr2AC lattice parameters a and c are deviations theoretically from 0.1 to 2% and 0.15-2.87% compared with experimental work. Also, the Zr2AC MAX phases are metallic characters and the conductivity differs depending on the type of the Zr2AC(different A element) MAX phases. Its concluded that the Zr2AC MAX phases are stiff, isotropic elastic properties and high machinability with damage tolerance and hardness levels ranging from 3.5 to 13.02 Gpa. The Zr2AC MAX phases are also resistant to corrosion, thermal shock, and oxidation as well as lightweight. In addition, at elevated temperatures the transition from brittle to plastic behavior can be occurred in the Zr2AC MAX phase. The Zr2AC MAX phase's optical properties are anisotropic such as electrical conductivity and mechanical properties. This review study provides a comprehensive details assisting researches to deal with Zr2AC MAX phase potentially for different applications.

Synthesizinge a novel Zr2Al-GNS MAX phase ceramic with superior electrical properties using pressureless sintering technique.

A unique Zr2Al-GNS MAX phase ceramic supported nanographene sheet was prepared using a cost-effective pressureless sintering technique under relatively low temperature. An experimental investigation was conducted to explore the lattice parameters using different temperatures, such as 1000, 1150, and 1300 °C. To characterize the crystal structure of the MAX phase ceramic, X-ray diffraction, field emission scanning electron microscopy imaging, energy-dispersive X-ray spectroscopy (EDX), high-resolution transmission electron microscopy (HRTEM), and selected area diffraction (SAED) were utilized. The results revealed that the pressureless sintering technique was successfully utilized to synthesize the Zr2Al-GNS MAX phase ceramic under 1150 °C with a low impurity ratio of secondary phases such as Zr3AL2, Zr3AL5, and ZrC components. The high percentage of the Zr2Al-GNS MAX phase ceramic was obtained at 49.0% at 1150 °C compared with different temperatures. The BET surface area (SBET), pore volume, and pore size were also investigated. The SBET of the prepared Zr2Al-GNS MAX phase was increased to 30% using graphene nanosheet, while the porosity was highly decreased to 8% from its original value. The electrical properties were also studied in this research for potential applications, such as the absolute value of impedance (Z), absolute value of admittance (Y), induction (L), capacitance (C), resistance (R), conductance (G), susceptibility (B), and phase angle (Ï´). It was found that the capacitance and the phase angle were improved using the prepared Zr2Al-GNS MAX phase ceramic, depending on the frequencies. The results presented here may facilitate the improvements in the features of the MAX phase type of Zr2Al-GNS-enhanced one-layer nanographene sheet for electrical applications ceramic.