Fig. 2: Strain-driven domain engineering for tailoring dielectric tunability.
From: Colossal and tunable dielectric tunability in domain-engineered barium strontium titanate
a Landau-Ginzburg-Devonshire (LGD) model-calculated temperature-strain phase diagram of the film plane-normal polarization and domain-wall variants in polydomain BST80 thin films. Arabic numerals denote various thermodynamically predicted domain structures (see Fig. S8). The dots correspond to the expected strain of BST80 coherently strained on SrTiO3(STO)(100), GdScO3(GSO)(110), SmScO3(SSO)(110), KTaO3(KTO)(100), and NdScO3(NSO)(110) (from left to right). b LGD model-calculated out-of-plane dielectric permittivity for BST80 films under different strains corresponding to selected substrates. c Measured dielectric permittivity, at 10 kHz, of the BST80 films grown on Ba0.5Sr0.5RuO3(BSRO) or SrRuO3(SRO)-electroded NSO(110), KTO(100), SSO(110), GSO(110) and STO(100) substrates. d Tunability data from c, plotted as a function of the BST80 film in-plane lattice parameter described in the Methods section. The inset shows inverse tunability data. The black dots denote the tunability for the BST80/SSO under 100 mV AC bias. Dotted lines indicate fits to the data.
