Real time in situ x-ray diffraction study of the crystalline structure modification of Ba0.5Sr0.5TiO3 during the post-annealing

Abstract

We report about an in situ study of crystalline structural changes during thermal treatment of a Ba0.5Sr0.5TiO3 (BSTO) film grown on MgO. The study covers the complete cycle of heating, annealing and cooling and reveals simultaneous phenomena of phase transitions and strain evolution, which have been characterized by in situ 2D reciprocal space mapping (2D-RSM) using high-resolution synchrotron x-ray diffraction in coplanar and grazing incidence geometries. In this way, temperature induced phase transformation from the BSTO2 to the BSTO1 phase has been monitored and the appearance of a further crystalline phase was detected. Moreover, for both BSTO phases, transitions between in-plane compressive and tensile states have been determined during thermal treatment. Furthermore, a contraction of the out-of-plane lattice components has been observed during the annealing phase while the in-plane lattice components remain leading to the change of the residual in-plane strain towards tensile state. The in situ 2D-RSM findings provide valuable and versatile insights into strain engineering and structure modification upon thermal treatment.

Experimental Band Structure of Pb(Zr,Ti)O3: Mechanism of Ferroelectric Stabilization

“…It is well established that the paraelectric to ferroelectric transition involves a structural transition from high to low symmetry, with consequent displacement and offcentering of the atoms from their symmetric positions. [2][3][4] At microscopic level, such non-centrosymmetric configuration of the atomic positions in the unit cell is consistent with a picture of dipoles aligned along the direction of the internal electric field.…”

Kinetic Simulations of in-situ Diffracted Intensities During Pulsed Laser Deposition of LuFeO3: Effect of Pulse Laser Frequency

“…The PLD chamber is installed on a multipurpose heavy-duty x-ray diffractometer on the NANO beamlime at synchrotron KARA (KIT, Karlsruhe, Germany) [30][31][32] . The intensity of the LuFeO 3 0003 quasiforbidden diffraction spot (AB intensity) was acquired in situ during the deposition, using an one-dimensional (1D) Mythen detector (Dectris) having 1280 channels with the channel size of 50 µm, the acquisition time was 1 s. The detector was placed 1118 mm behind the sample giving an angular resolution of 0.00257 degree per channel.…”

Combined In Situ XRD and Ex Situ TEM Studies of Thin Ba0.5Sr0.5TiO3 Films Grown by PLD on MgO

“…The measured profile of the diffraction intensity along the channels of the Mythen detector is drawn in Figure 1b which represents the 3D time scan of the diffraction profile corresponding to the BSTO XRD002 reflection recorded during the interval PLD growth. A more detailed description of the experimental setup is given by Bauer et al [10] The number of laser pulses was set to 600 for steps 1−6 while the number of pulses was increased to 1200 for steps 7 and 8 (cf. Figure 1d).…”