The Research Of Magnetoelectric Coefficient Automation Measurement System

Magnetoelectric effect is the phenomenon in the material that induction of polarization by a magnetic field or of magnetization by an electric field. In recent years, we observed significant magnetoelectric coupling in materials and magnetoelectric effect received widespread attention. It has a good prospect which can be used as a magnetic sensor to detect weak magnetic field, in terms of microwave devices, it can be made microwave tunable filters and phase shifters, and you can also use the characteristics that the voltage gain is very high under magnetic resonance to produce power conversion devices. The magnetoelectric voltage coefficient, as the main indicator to measure the level of magnetic effect, its setup platform and standard is particularly important.The paper starts with the measuring principle of magnetoelectric voltage coefficient and selects the dynamic testing method. Applying a weak alternating magnetic field under a bias filed, we will measure the induced voltage at the surface of the magnetoelectric material and obtain the magnetoelectric voltage coefficient after further calculations. We put forward the overall scheme of the magnetic test system after comparative analysis of several aspects such as the DC magnetic field generation and detection, the induced voltage measurement, the hardware interfaces, software platform and so on. We design an automation control software based on Java Swing on the computer to control the output of DC source and AC source, we also use the software to get data from Gauss meter, multimeter and lock-in amplifier. When measuring the hardware module performance, we obtain the parameters such as the DC magnetic range 0~4000 Oe, the AC magnetic field amplitude 0.4~1 Oe and the frequency range 0~200 k Hz. System software uses serial polling control technology to achieve the orderly control multiple devices and the use of multi-threading technology to overcome the problem of mission operations block access UI components so that the chart updates and data reception synchronization. Finally, the system tests Terfenol-D/PZT/Terfenol-D composites, including under 1 k Hz?1 Oe low frequency alternating magnetic field, the relationship between the DC bias magnetic and the magnetoelectric voltage coefficient and under certain DC bias field, the relationship between frequency of alternating magnetic and magnetoelectric voltage coefficient, the results meet the characteristics of the material and verify the correctness of the system. In addition, we gain the final measurement accuracy including that of lock-in is 0.01 m V/cm·Oe and multimeter is 0.05 m V/cm·Oe. Both lock-in and multimeter are used to measure the output voltage, they ensure the accuracy and extend the frequency range of the magnetoelectric response.