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Framework materials yield to pressure

Date:
June 11, 2015
Source:
International Union of Crystallography
Summary:
High pressure has become an indispensable research tool in the quest for novel functional materials. High-pressure crystallographic studies on non-porous framework materials based on coordination compounds are markedly on the rise, enabling the unraveling of structural phenomena and taking us a step closer to the derivation of structure-property relationships.
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This is a cobalt II octahedral packing diagram as viewed in the (001) plane.
Credit: Yakovenko et al

Pressure is a powerful thermodynamic variable that enables the structure, bonding and reactivity of matter to be altered. In materials science it has become an indispensable research tool in the quest for novel functional materials.

Materials scientists can exploit the effectiveness of pressure for probing and tuning structural, mechanical, electronic, magnetic and vibrational properties of materials in situ; crystallography plays a crucial role, enabling on the one hand the unravelling of structural phenomena through a better understanding of interactions, and on the other shedding light on the correlation of structure and properties.

With high pressure promoting effects such as magnetic crossover, spin transitions, negative linear compressibility, changes in proton conductivity, or even phase transitions that generate porous structures, high-pressure crystallographic studies on dense framework materials are on the rise. More generally, coordination compounds are a fascinating class of materials for high-pressure crystallographic studies, compared with purely organic compounds; they have an inherent extra degree of flexibility for responding to moderate applied pressures, as the geometry at the metal centre can undergo marked changes, whereas other primary bond distances and angles remain largely unaffected.

A group of scientists demonstrate that pressure offers a novel approach for generating new phases and exploring the structure-property relationships of molecular materials.

In their study the researchers present a high-pressure crystallographic study of α -Co(dca)2, including the structural determination of the high-pressure phase γ -Co(dca)2. The pressure-dependence of the atomic structure was probed within a diamond-anvil cell using synchrotron-based powder diffraction methods.

Future work from the group based at Argonne National Laboratory will involve investigations of the pressure-dependent structures of further transition metal dicyanamides, including members of the iso-structural α-MII(dca)2 family as well as other polymorphs, to uncover any universality or metal-ion dependence associated with the α→γ transition, and if other new phases can be generated.


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Journal References:

  1. Andrey A. Yakovenko, Karena W. Chapman, Gregory J. Halder. Pressure-induced structural phase transformation in cobalt(II) dicyanamide. Acta Crystallographica Section B Structural Science, Crystal Engineering and Materials, 2015; 71 (3): 252 DOI: 10.1107/S2052520615005867
  2. Francesca P. A. Fabbiani. Probing the structure of framework materials by high pressure and the example of a magnetic, non-porous coordination polymer. Acta Crystallographica Section B Structural Science, Crystal Engineering and Materials, 2015; 71 (3): 247 DOI: 10.1107/S2052520615009427

Cite This Page:

International Union of Crystallography. "Framework materials yield to pressure." ScienceDaily. ScienceDaily, 11 June 2015. <www.sciencedaily.com/releases/2015/06/150611114413.htm>.
International Union of Crystallography. (2015, June 11). Framework materials yield to pressure. ScienceDaily. Retrieved May 23, 2017 from www.sciencedaily.com/releases/2015/06/150611114413.htm
International Union of Crystallography. "Framework materials yield to pressure." ScienceDaily. www.sciencedaily.com/releases/2015/06/150611114413.htm (accessed May 23, 2017).

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