平成２１年度　実績報告書

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教育研究プラットフォームIDER研究成果/ポストドクター・GCOE研究員Fig. 1 The photo of RF SQUID (left) and the substrate resonator (right). Fabrication of High Tc RF SQUIDs on Bicrystal Substrate Xiangyan Kong D epartment of System s Innovation, Graduate School of Engineering , Osaka University Itozaki Laboratory Abstract High Tc RF SQUID magnetometer has been designed and fabricated with YBCO film deposited on bicrystal substrate. The substrate resonator with planar concentrator has also been fabricated and evaluated. The white noise level of the above combination can be up to 0.8 p T/rtHz and has been successfully applied in NDE to reduce the environmental noise. Introduc tion The washer size of the RF SQUID magnetometer is 3.5 mm in diameter and the loop side length is 100 µm. The junction width is 4 µm. The inductance of the SQUID is 150 pH. The matching substrate resonator is single STO with thickness of 0.5 mm. A planar concentrator with YBCO film is also fabricated on it. Experimental The YBCO film was deposited on the STO bicrystal substrate with pulsed laser deposition (PLD) method. The transition temperature is above 90 K. And the pattern was transferred with stan dard photolithography and Ar+ ion milling. The electric properties of RF SQUID magnetometer and the substrate resonator (Fig.1) were also evaluated. With the setup system, the magnetic particle with diameter of 80.6 µm and 129 µm on a glass was successfull y detected. Results and Discussion With the SQUID electronics from Juiech, the noise of the combination of RF SQUID magnetometer and substrate resonator with flip - chip configuration was evaluated. The field sensitivity is 0.8 pT/rtHz in magnetic shielde d room as shown in Fig. 2 . Fig ure 3 is the output of the RF SQUID magneto meter when scanning above a magnetic particle with different size. The distance between RF SQUID and magnetic particle is 7.7 mm. This method is very useful in food safety and industry. 0 5 10 15 20 25 30 0.0 0.5 1.0 1.5 2.0 2.5 3.0 Scannning Distance (cm) YBCO194:YBCO172 (d=7.7mm) ) T n ( t u p t u O D I U Q S Phi 80.6 um Phi 129 um Fig. 3 The signal of magnetic particle detected by RF SQUID magnetometer . Fig. 2 The white noise of RF SQUID magnetometer combined with substrate reson a tor 87

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