Intercalation and Deintercalation Processes for Ammoniated 1T-TaS2

✍ Scribed by Lisa Diebolt; William Glaunsinger; Michael McKelvy

• Publisher: Elsevier Science
• Year: 1999
• Tongue: English
• Weight: 176 KB
• Volume: 145
• Category: Article
• ISSN: 0022-4596
• DOI: 10.1006/jssc.1999.8293

✦ Synopsis

The intercalation and deintercalation processes for nearly stoichiometric 1T-TaS 2 have been investigated by X-ray powder di4raction, thermogravimetric analysis, di4erential scanning calorimetry, and mass spectrometry. The maximum ammonia stoichiometry that has been prepared for a 4-month reaction time is (NH ؉ 4 ) 0.06 (NH 3 ) 0.07 (1T-TaS 2 ) 0.06 \ . The reaction mechanism can be accounted for within a redox-rearrangement model in which part of the NH 3 is oxidized to NH ؉ 4 upon intercalation, with the NH ؉ 4 decomposing at the host-layer edges to liberate NH 3 and H upon deintercalation. All intercalation compounds prepared could be deintercalated at relatively low temperatures. The intercalates retained some 1T-TaS 2 host material, which may be associated with the rather low concentration of intercalant combined with intercalation reaction fronts that only partially penetrate the host in a nucleation and growth process. This study indicates that ammoniated 1T-TaS 2 is a unique redoxrearrangement intercalation system.