Preparation of the superconducting magnetostatic wave device by the heterostructure of the oxide superconductor/ferromagnet.

在超导体的电子学应用方面，SQUID或SFQ电路最大限度地利用了超导体的磁通量子化特性。然而，在超导微波器件领域，仅注意到低的表面电阻。因此，我们注意到通量量子在微波器件中的应用。在这种思路下，我们研制了超导静磁波器件的原型装置，其中超导涡旋和静磁波在铁磁物质中传播。涡旋与静磁波相互作用的影响表现在两个方面。其一是静磁波的磁能会被涡旋吸收。另一种是由于静磁波驱动的涡旋运动，超导体向正常态的转变。为了验证这一考虑，我们进行了两个实验，即，静磁波的测量 ...更多信息 超导体的I-V测量和超导体的I-V测量分别用于测量超导体中的涡旋情况和静磁波传播情况，通过静磁波的传播监测超导态和正常态的开关行为。此外，当超导体处于正常状态时，静磁波必然被吸收。这是新型超导微波器件的第一步，即利用涡旋与静磁波器件的相互作用来控制开关器件，这种超导静磁波器件适合于制作超导体和铁磁体的双层外延薄膜。现阶段，Y-Fe石榴石（YIG）铁氧体被广泛用作静磁波传播器。然而，YIG不能在钙钛矿型超导体上生长。因此，我们的动机是朝向寻找新的磁性材料作为静磁波的波导，以建构异质磊晶双层超导体。所用材料为钙钛矿型锰氧化物Pr_<0.85>Ca_<0.15>MnO_3（PCMO）。X射线衍射分析表明，在Nb-SrTiO_3（100）上外延生长出了高质量的薄膜。在25 K ~ 300 K的温度范围内，对材料的电性能进行了评价。结果表明，在液氮温度为77 K时，PCMO具有合适的Δ r和较低的损耗角正切。这意味着PCMO可用于微波应用。此外，形成了PCMO/YBCO异质结构作为超导静磁波器件的带阻滤波器。在本实验中，超导直线上的微波可以在PCMO薄膜中激发出静磁波。少

On the electronic application of the superconductor, SQUID or SFQ circuit have utilized the feature of the flux quantumization, up-to-maximum. However, only the low surface resistance is noted for the field of superconducting microwave device. Thus, we have noted the application of the flux quantum to the microwave devices. In this idea, we have investigated and fabricated the prototype device of the superconducting magnetostatic wave device, in which the superconducting vortices and the magnetostatic wave propagating in the ferromagnetic matter. The effects of the interaction between the vortices and the magnetostatic wave are following two points. One is the magnetic energy of the magnetostatic wave will be absorbed by the vortices. The other is the switch of the superconductor to the normal state because of the vortices motion driven by the magnetostatic wave. In order to verify the consideration, we have performed two experiments, i.e., the measurement of the magnetostatic wave pro … More pagation for the situation of vortices in the superconductor, and the I-V measurement of the superconductor for the situation of the magnetostatic wave propagation.In those measurement, we have monitored the switching behavior of the superconducting state and normal state by the propagation of the magnetostatic wave. Furthermore, the magnetostatic wave is certainly absorbed when the superconductor is the normal state. This is the first step of the novel superconducting microwave device which is the switching device controlled by the interaction between vortices and the magnetostatic wave device.The superconducting magnetostatic wave device is suitable by the fabrication as the bilayered epitaxial thin films of the superconductor and the ferromagnet. In the present stage, Y-Fe garnet(YIG) ferrite is widely used as the magnetostatic wave propagator. However, the YIG cannot be grown on the perovskite type superconductor. Thus, our motivation is toward to the search of the new magnetic material for the waveguide of the magnetostatic wave which can construct the heteroepitaxial bilayer with the superconductor. The material we have noted is perovskite type manganite Pr_<0.85>Ca_<0.15>MnO_3 (PCMO).As the first step, we have prepared the PCMO thin film. The X-ray diffraction shows the high quality epitaxial thin films on the Nb-SrTiO_3(100). In the next, the electric properties are evaluated with the temperaturerange of 25 K〜300K. As the results, the LN_2 temperature of 77K, the PCMO has suitable Δ_r and low loss tangent. This means the PCMO is useful for the microwave application. Furthermore, the PCMO/YBCO heterostructure is formed as the band elimination filter of the superconducting magnetostatic wave device. In this experiment, microwave in the superconducting straight line can excited the magnetostatic wave in the PCMO thin films. Less