# Effect of high pressure and temperature on nanocrystalline $Fe_2O_3$ and $TiO_2$

Vaidya, SN and Karunakaran, C and Aruna, ST (2001) Effect of high pressure and temperature on nanocrystalline $Fe_2O_3$ and $TiO_2$. In: High Pressure Research, 21 (2). pp. 79-92.

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## Abstract

Nanocrystalline (n) \gamma $Fe_2O_3$ and n $TiO_2$ (anatase) prepared by gel combustion technique and n $TiO_2$ (rutile) prepared by sol-gel technique were subjected to high pressures and high temperatures in a toroid anvil aparatus. A new polymorph of $Fe_2O_3$ belonging to hexagonal system, with $a = 10.752A^o$ and $c = 17.806A^o$, was found in the material quenched from 5.2 GPa and 900°C. n $TiO_2$ (anatase) sintered at 5.2 GPa pressure and 700°C temperature transformed to rutile structure, as expected. However, n $TiO_2$ (rutile) did not show any phase changes. At 27°C, n \gamma $Fe_2O_3$ and n $TiO_2$ (anatase) showed transition to an apparently amorphous state above 8 GPa.

Item Type: Journal Article Copyright of this article belongs to Taylor and Francis. High pressure;High temperature;Nanocrystals;FezO3;TiOz;Rutile; Anatase. Division of Chemical Sciences > Inorganic & Physical Chemistry 07 Aug 2008 19 Sep 2010 04:48 http://eprints.iisc.ernet.in/id/eprint/15491