Study On Preparation Of Resonator Used In Magnetomechanical Marker

Magnetomechanical electronic article surveillance(EAS) system is one of the most advanced EAS systems in the world. The magnetomechanical marker, which is the key element of magnetomechanical EAS system, has remarkable consumption and broad market prospect. However, the preparation technology of magnetomechanical marker has been monopolized by Sensormatic Company for many years. Up to now, there are no intensive researches in China. How to develop fabrication technology and share the broad market are very important mission for Chinese researchers. Therefore, in this work, preparation technology of the amorphous resonator, which is the key part of the magnetomechanical marker, has been intensively investigated.The single-roller melt-spinning technique, which is the key technology for fabrication of the amorphous resonator, has been investigated and the amorphous resonator with58kHz resonant frequency that can be applied in commercial field has been successfully prepared. To enhance the resonant amplitude of resonator further, the composition of resonator, the heat treatment technology and the preparation of resonator with radian have been investigated. Some of main results are listed as follows:1. The cooling rate of amorphous ribbon is controlled by rotate speed of copper roller; The thickness of ribbon is determined by the distance between nozzle and roller when the jet pressure of nitrogen is suitable; The surface quality of ribbon is determined by the jet pressure of nitrogen when the rotate speed of copper roller and the distance between nozzle and roller are constant.2. The increasing glass transition forcing elements B and Si can facilitate amorphous transition. However, the B and Si can not obviously enhance the resonant amplitude. The magnetic elements Co and Ni can affect the resonant amplitude. 3. The enhancement effect by annealing under a perpendicular magnetic field is more obvious than in the parallel magnetic field to the ribbon plane.4. The ribbons with radian can be successfully prepared through annealing with a special annealing clip. By this way, the clamping effect is weakened and the resonant amplitude is obviously enhanced.