Figure 7. Real conductivity [σ₁(ω)] of a 90-μm-thick BSTS sample at 10 K, 50 K, 90 K and 150 K. Experimental data were taken in the sequence: 10 K → 50 K → 90 K → 150 K → 10 K → 50 K → 90 K → 150 K.