Transformation of LiTi2O4from Spinel to Ramsdellite on Heating

✍ Scribed by Richard K.B. Gover; John T.S. Irvine; Adrian A. Finch

• Publisher: Elsevier Science
• Year: 1997
• Tongue: English
• Weight: 311 KB
• Volume: 132
• Category: Article
• ISSN: 0022-4596
• DOI: 10.1006/jssc.1997.7479

✦ Synopsis

Time of flight powder neutron diffraction has been used to study the structural changes on heating LiTi 2 O 4 from 25 to 1000°C. A phase transition from the spinel to the ramsdellite form occurred between 875 and 925°C; the two structure types coexisted, apparently in equilibrium over much of this range. About 300°C below the transition, an anomalous change in the spinel structure was seen to occur. This anomaly was only observed in the parameters associated with Li and is thought to reflect migration of about 10% of the Li atoms from the 8a site. Above 925°C, the ramsdellite form is stable and the structure was retained after rapid cooling. The structure of the high temperture ramsdellite form was refined by Rietveld analysis using the Pbnm space group. The refinement gave final R wp and R p values of 2.91 and 3.74%, respectively.

EXPERIMENTAL

A two stage synthesis route was chosen involving Li Ti O , TiO , and Ti metal, using the Eqs.

[1] and [2].