Multipurpose diffractometer for in situ X-ray crystallography of functional materials

Abstract

Laboratory X-ray diffractometers play a crucial role in X-ray crystallography and materials science. Such instruments still vastly outnumber synchrotron facilities and are responsible for most of the X-ray characterization of materials around the world. The efforts to enhance the design and performance of in-house X-ray diffraction instruments benefit a broad research community. Here, the realization of a custom-built multipurpose four-circle diffractometer in the laboratory for X-ray crystallography of functional materials at Tel Aviv University, Israel, is reported. The instrument is equipped with a microfocus Cu-based X-ray source, collimating X-ray optics, four-bounce monochromator, four-circle goniometer, large (PILATUS3 R 1M) pixel area detector, analyser crystal and scintillating counter. It is suitable for a broad range of tasks in X-ray crystallography/structure analysis and materials science. All the relevant X-ray beam parameters (total flux, flux density, beam divergence, monochromaticity) are reported and several applications such as determination of the crystal orientation matrix and high-resolution reciprocal-space mapping are demonstrated. The diffractometer is suitable for measuring X-ray diffraction in situ under an external electric field, as demonstrated by the measurement of electric-field-dependent rocking curves of a quartz single crystal. The diffractometer can be used as an independent research instrument, but also as a training platform and for preparation for synchrotron experiments.

“Forbidden” Polarisation and Extraordinary Piezoelectric Effect in Organometallic Lead Halide Perovskites

“…[ 58 ] The concern is that the electric‐field‐generated current could raise the temperature of the sample through Joule heating, with resulting thermal strain interfering with electro‐mechanical strain [ 59 ] (see Figure S13, Supporting Information). To gain further insights into the structural mechanisms of the electric‐field‐induced strain, we investigated MAPbBr 3 using single crystal x‐ray diffraction [ 60 ] (see Experimental Section and Figure S14, Supporting Information).…”

“…XRD Measurements: X-ray diffraction experiments were performed at the custom-built four-circle x-ray diffractometer for in situ crystallography of functional materials in Tel Aviv University. [60] The diffractometer was equipped with Cu-based microfocus X-ray source, double-crystal monochromator (fully suppressing Kalpha2 line), motorized Eulerian cradle, two-dimensional pixel area detector (PILATUS 1 m), and the high-temperature temperature cell (Forvis Technologies). Electric field was produced using HAMEG electric signal arbitrary function generator and amplified using Matsusada high-voltage amplifier.…”

Identification of a coherent twin relationship from high-resolution reciprocal-space maps

“…Such experiments are facilitated by the recent progress in synchrotron-based and home-laboratory X-ray sources, availability of pixel area detectors, beam conditioning systems and big-data exchange protocols (see e.g. Dyadkin et al, 2016;Girard et al, 2019;Gorfman et al, 2021).…”

“…This section illustrates the recognition of a coherent twin relationship in a twinned BaTiO 3 crystal. We performed highresolution reciprocal-space mapping measurements at the dedicated home-laboratory X-ray diffractometer at Tel Aviv University (Gorfman et al, 2021). Following the determination of the average orientation matrix using CrysAlisPro software (the averaging is performed over all the domains present in the X-ray beam), we collected high-resolution reciprocal-space maps of the diffraction intensity distribution around 102, 002, 222 and 103 reflections.…”

Permissible domain walls in monoclinic ferroelectrics. Part II. The case of MC phases

“…Such splitting is routinely measured in high-resolution singlecrystal diffraction experiments (Gorfman & Thomas, 2010;Vergentev et al, 2016;Zhang et al, 2018;Choe et al, 2018;Gorfman et al, 2011Gorfman et al, , 2020Gorfman et al, , 2021Gorfman et al, , 2022. Therefore, expression (18) finds direct application in recognizing connected domain pairs within 3D diffraction patterns.…”