title: Acoustic properties of alumina colloidal/polymer nano-composite film on silicon.
abstract: Alumina colloidal/polymer composite films on silicon substrates have been successfully fabricated using the sol-gel method, in which the crystallite sizes of alumina are between 20 and 50 nm. The density and ultrasonic phase velocities in these films with different alumina ratios from 14% to 32% were measured at the desired operating frequency. We have proved that the density, acoustic phase velocities, and hence the acoustic impedance of the nano-composite films increase with the alumina content, which gives us another option of tailoring the acoustic impedance of the nano-composite film for making the matching layer of high-frequency medical ultrasonic transducers.
authors: Rui
authors: R
authors: Zhang
authors: Wenwu
authors: W
authors: Cao
authors: Qifa
authors: Q
authors: Zhou
authors: Jung Hyui
authors: JH
authors: Cha
authors: K Kirk
authors: KK
authors: Shung
authors: Yuhong
authors: Y
authors: Huang
mesh_terms: D000162:Acoustics; D000537:Aluminum Oxide / Q000737:chemistry*; D003102:Colloids / Q000737:chemistry; D003198:Computer Simulation; D008567:Membranes, Artificial; D008956:Models, Chemical; D049329:Nanostructures / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry; D011829:Radiation Dosage; D011874:Radiometry; D012542:Scattering, Radiation; D012825:Silicon / Q000737:chemistry*
chemical_list: D003102:Colloids; D008567:Membranes, Artificial; D011108:Polymers; D000537:Aluminum Oxide; D012825:Silicon