Structural Evolution of Tin Dioxide Nanoparticles under Acoustic Shocked Conditions for Aerospace Applications─Implications of Other Rutile-Type Dioxides Based on Superheating Approaches
Sivakumar Aswathappa, Lidong Dai, S. Sahaya Jude Dhas, Raju Suresh Kumar, Abdulrahman I. Almansour, S. Arumugam, Muthu Devaraj, Mowlika Varadhappa Reddy
Abstract
Nanoscale materials have wide applications in extreme conditions, including those related to aerospace- and defense-based technological aspects. However, for these kinds of applications, the sustainability of the crystal structure and related properties is highly required. In the present work, we investigate the rutile-type hexagonal-shaped SnO 2 NPs’ crystallographic, optical, and magnetic structural stabilities under acoustic shock wave-loaded conditions, and the observed structural stability results are compared with similar hexagonal-shaped rutile-type TiO 2 NPs under shocked conditions. From the observed X-ray diffraction results of the SnO 2 NPs, the rutile space group P 4 2 / mnm remains constant at 200 shock conditions without any structural deformations and distortions. The band gap energy is slightly increased due to the formation of surface defects, and the obtained values of band gap energy are found to be 3.55, 3.61, and 3.72 eV for the 0, 100, and 200 shocked conditions, respectively. According to the magnetic property results, the weak ferromagnetic state remains unaltered, and the thermal stability of the SnO 2 NPs is also unchanged, which demonstrates the absence of structural phase transitions under shocked conditions. However, the similar analogue-structured material of rutile-TiO 2 NPs transformed to the anatase phase after exposure to 90 shocks. Based on the observed overall structure–property stabilities and relationships of the SnO 2 and TiO 2 NPs, SnO 2 NPs have a high degree of structural stability under dynamic shocked conditions because of their higher thermal conductivity, and the observed results are discussed based on the shock wave-induced superheating approach. Due to their impressive stability profiles, SnO 2 NPs are highly deserving candidates for applications in extreme conditions, which include aerospace, defense, laser operation, and gas sensing.