Title : Development of Magnetic Field Sensors Using Bismuth – Substituted Garnets Thin Films with In - Plane Magnetization

Dissertation Title : Development of Magnetic Field Sensors Using Bismuth – Substituted Garnets Thin Films with In-Plane Magnetization Iulian Nistor, Ph.D., 2006 Dissertation Directed By: Professor of Engineering Isaak D. Mayergoyz, Electrical and Computer Engineering Department, and Dr. Charles Krafft, Laboratory for Physical Sciences In the dissertation, the use of magnetic single crystal Bismuth-substituted iron garnet thin-films with giant magneto-optical effect as optical sensors for measuring high frequency (up to 1GHz), low intensity magnetic fields is discussed. The advantages of these sensors are high intrinsic sensitivity and the possibility of tailoring the field range of the sensor. The design of these sensors is based on single crystal epitaxial garnet thin films grown by liquid phase epitaxy method from a flux melt. The garnet thin films are fully characterized using various magnetic and optical techniques. The melt compositions that allow for the growth of films with in-plane magnetization, giant Faraday rotation per unit length, large negative uniaxial anisotropies and small cubic anisotropy are identified. The design of garnet based magnetic field sensors is performed and a noise equivalent magnetic field of Hz T μ 5 . 1 and a signal-tonoise ratio of 68dB are demonstrated. DEVELOPMENT OF MAGNETIC FIELD SENSORS USING BISMUTH – SUBSTITUTED GARNETS THIN FILMS WITH IN-PLANE MAGNETIZATION