Figure 24: Phase shift at 10 GHz by transmission through a coplanar microwave line (made of gold) on BSTO-0.45 thin film at −25°C. The line width is 200 μm, and the gap to the grounded areas is 10 μm (red curve) and 5 μm (black curve); see inset. The Curie temperature of BSTO-0.45 is below −50°C and therefore shows a weak tunability of phase shift at +25°C.