Speaker: Bo Iversen, University of Aarhus
Program Description:
For more than a century crystallography has essentially relied on static measurement of Bragg diffraction data to establish the time and space averaged structure of crystals. However, development of very intense high-energy synchrotron X-ray sources has moved structural science into new territory with a plethora of “in situ” and “operando” investigations of real materials in real time under realistic conditions. The Danish National Research Foundation Center for Materials Crystallography (cmc.chem.au.dk) has for the past decade pushed the frontiers of such dynamic investigations to study a wide range of advanced materials. One development has been the application of X-ray total scattering methods to study both crystalline and non-crystalline samples. Using special in situ reactors [1] we have followed nanocrystal nucleation and growth [2] and based on atomic scale structural insight shown that classical nucleation theories are far from the truth [3]. Here recent in situ studies of the formation of MOFs and bimetallic nanocatalysts will be discussed [4]. Thermoelectric materials constitute another focus area [5], and here subtle correlated disorder can be revealed using 3D-PDF analysis [6]. Finally, first results from a new operando setup allowing studies of materials under electrical and thermal gradients also will be discussed.
[1] a) Jensen et al., Angew. Chem. Intl. Ed. 2007, 46, 1113-1116. b) Becker et al., J. Appl. Crystallogr. 2010, 729–736
[2] a) Bremholm et al., Angew Chem. Intl. Ed. 2009, 48, 4788-4791. b) Tyrsted et al., Angew. Chem. Int. Ed. 2012, 51, 9030–9033, b) Jensen et al., J. Am. Chem. Soc. 2012, 134, 6785–6792, d) Saha et al., Angew. Chem. Int. Ed. 2014, 53, 3667 –3670, e) E. D. Bøjesen et al., Chem. Sci. 2016, 7, 6394 – 6406,
[3] Bøjesen & Iversen, CrystEngComm 2016, 18, 8332 - 8353
[4] a) Xu et al., Chem. Eur. J. 2019, 25, 2051 – 2058. b) Broge et al, Adv. Func. Mater. 2019, 29, 1902214
[5] a) Zhang et al., Nature Commun. 2016, 7, 10892. b) Zhang et al., Nature Comm 2017, 8, 13901. c) Zhang et al., Nature Comm. 2018, 9, 4716. d) Kasai et al., Nature Materials 2018, 17, 249-252. e) Zeuthen et al., J. Am. Chem. Soc. 2019, 141, 8146-8157
[6] a) Roth et al., IUCr-J 2018, 5, 410–416.b) Roth & Iversen Acta Crystallogr. Sect. A 2019, 75, 465–473
