Tschermigite from thermal fields of Southern Kamchatka: high-temperature transformation and peculiarities of IR-spectrum

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Marco E. Ciriotti
Messaggi: 25808
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Tschermigite from thermal fields of Southern Kamchatka: high-temperature transformation and peculiarities of IR-spectrum

Messaggio da Marco E. Ciriotti » mer 07 ago, 2019 13:04

Referenza:
▪ Zhitova, E.S., Sergeeva, A.V., Nuzhdaev, A.A., Krzhizhanovskaya, M.G., Chubarov, V.M. (2019): Tschermigite from thermal fields of Southern Kamchatka: high-temperature transformation and peculiarities of IR-spectrum. Zapiski RMO, 148(1), 100-116.

Abstract:
Tschermigite, (NH4)Al(SO4)2∙12H2O, is a widespread mineral in efflorescence at geothermal fields associated with Kambalny and Koshelevsky volcanoes (Southern Kamchatka, Russia). The determined temperature ranges of stability of tschermigite and products of its high-temperature evolution by in situ powder X-ray diffraction: tschermigite (23—60°C) → X-ray amorphous phase (70—200 °C) → godovikovite (210—390°C) → millosevichite (380—>620°C). This implies decomposition of tschermigite (23—60°C) first to the interim X-ray amorphous phase (probably melt) from which godovikovite is then formed, without direct transformation of tschermigite to godovikovite, as it was suggested in some papers previously. Deammonization of godovikovite to millosevichite occurs at 380—390°C. Thermal expansion coefficients are given for tschermigite, godovikovite and millosevichite with discussion on some peculiarities on their formation. Regarding IR bands that refer to ammonium ion: ν3 (~1430 cm–1) split, ν1 (~3100 cm–1) active, what attests about at least partial shift of N (NH4+) in tschermigite crystal structure from site 4b (S6) to site 8c (С3). In O—H stretching region, higher wavenumber band (~3380 cm–1) corresponds to «extraframework» water, while the observed band ~2950 cm–1 corresponds to water coordinating Al.
Marco E. Ciriotti

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Massimo Russo
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Re: Tschermigite from thermal fields of Southern Kamchatka: high-temperature transformation and peculiarities of IR-spec

Messaggio da Massimo Russo » mer 07 ago, 2019 16:21

Marco riesci a procurarmi il pdf?

Massimo
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Massimo Russo
INGV - Osservatorio Vesuviano

"Un minerale senza nome è solo un inutile pezzo di pietra" (Massimo Russo)

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Marco E. Ciriotti
Messaggi: 25808
Iscritto il: ven 25 giu, 2004 11:31
Località: via San Pietro, 55 I-10073 Devesi/Cirié TO - Italy
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Re: Tschermigite from thermal fields of Southern Kamchatka: high-temperature transformation and peculiarities of IR-spec

Messaggio da Marco E. Ciriotti » mer 07 ago, 2019 16:38

Marco riesci a procurarmi il pdf?
Sì, ma è in cirillico.
Marco E. Ciriotti

«Things are interesting only in so far as they relate themselves to other things»

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Massimo Russo
Messaggi: 6987
Iscritto il: mar 29 giu, 2004 12:00
Località: via Consalvo, 120/A, I-80125 Napoli
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Re: Tschermigite from thermal fields of Southern Kamchatka: high-temperature transformation and peculiarities of IR-spec

Messaggio da Massimo Russo » mer 07 ago, 2019 16:50

Ok va bene lo stesso.

Massimo
---------------------------------------
Massimo Russo
INGV - Osservatorio Vesuviano

"Un minerale senza nome è solo un inutile pezzo di pietra" (Massimo Russo)

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Marco E. Ciriotti
Messaggi: 25808
Iscritto il: ven 25 giu, 2004 11:31
Località: via San Pietro, 55 I-10073 Devesi/Cirié TO - Italy
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Re: Tschermigite from thermal fields of Southern Kamchatka: high-temperature transformation and peculiarities of IR-spec

Messaggio da Marco E. Ciriotti » mer 07 ago, 2019 18:57

Spedito.
Buona lettura.
Marco E. Ciriotti

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