Abstract
NdFe11Ti has been investigated extensively since 1990. Magnetic properties can be much improved by gas interstitial atom modification (GIM). The influences on magnetic property include Curie temperature, saturation magnetization, coercivity and energy product. In this study, textured NdFe11Ti and NdFe11TiNx thin films were prepared by dc magnetron sputtering with proper deposition and nitriding conditions. Our targets were prepared by induction melting, sealing in quartz tubes under Ar atmosphere and annealing for a week at 1000℃. NdFe11Ti thin films can only be obtainable with substrate temperature ranging from 450℃ to 500℃. The best nitriding condition was 100 Torr pure N2, 450℃, 10min. The best room temperature magnetic properties of textured NdFe11TiNx thin film: saturation magnetization 12.0kG, remanence magnetization 11.3kG, coercivity 2.8kOe and the maximum energy product 24.1MGOe. At 5K, the maximum energy product is 93.8MGOe. Besides fundamental measurements, magnetic viscosity, exchange spring effect and nucleation field were investigated by magnetic aftereffect and dM plot. The exchange spring effect between hard magnetic phase (NdFe11TiNx) and soft magnetic phase (Fe) exists in NdFe11TiNx thin films. The nucleation field ranges 2.0~2.3kOe, and activation volume ranges 1~5x10-17cm3. Magnetic aftereffect coefficient and irreversible susceptibility are 23.07G/sec and 34.74G/Oe, respectively. Magnetic aftereffect constant (Sv) is 0.8Oe.