In Situ Infrared Spectra for Hydrous Forsterite up to 1243 K: Hydration Effect on Thermodynamic Properties

Liu, Dan; Sha, Wei E. I.; Smyth, Joseph R.; Zhang, Junfeng; Wang, Xiang; Zhu, Xi; Ye, Yu

doi:10.3390/min9090512

Cited by 5 publications

(6 citation statements)

References 70 publications

(191 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…conditions (e.g. Gillet et al 1991;Liu et al 2019b), and this study reveals that Fe incorporation further increases the magnitudes of these contribution. In addition, previous high-temperature studies have indicated that Fe decreases the thermal expansion coefficient in olivine solid solutions (Smyth and Hazen 1973;Smyth 1975; This is the peer-reviewed, final accepted version for American Mineralogist, published by the Mineralogical Society of America.…”

Section: Implicationsupporting

confidence: 57%

“…Kohlstedt et al 1996;Smyth et al 2006). The calculation revealed that hydration would further increase the magnitude of the anharmonic contribution to more than 9 % for the model of the heat capacities (Liu et al 2019b).…”

Section: Introductionmentioning

confidence: 93%

“…Next, the heat capacities were computed according to the vibrational frequency models proposed by Kieffer (1979) and Hofmeister (1987), and the anharmonic contribution to the heat capacities reached a percentage of 6 ~ 7 % when extrapolated to 2000 K, with respect to the harmonic approximation. Further, Yang et al (2015) and Liu et al (2019b) investigated the intrinsic anharmonicity in hydrous forsterite samples, since olivine can contain a significant amount of structural water (as This is the peer-reviewed, final accepted version for American Mineralogist, published by the Mineralogical Society of America.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

High-temperature and high-pressure Raman spectra of Fo89Fa11 and Fo58Fa42 olivines: Iron effect on thermodynamic properties

Liu

Guo

Smyth

et al. 2021

American Mineralogist

View full text Add to dashboard Cite

The intrinsic anharmonicity plays an important role in the thermodynamic properties of minerals at the high-temperature conditions of the mantle. To investigate the effect of iron on the thermodynamic properties of olivine, the most abundant mineral in the upper mantle, we measured in situ high-temperature and high-pressure Raman spectra of natural Fo 89 Fa 11 and synthetic Fo 58 Fa 42 samples. Fo 58 Fa 42 dissociates to enstatite + quartz + Fe 2 O 3 (+ Fe) at 893 K. All the Raman-active modes systematically shift to lower frequencies at elevated temperature, whereas to higher frequencies with increasing pressure. The A g mode at approximately 960 cm-1 is more sensitive to the variations of temperature and pressure than the other internal modes. The crystal-field splitting of the vibrational energy states gets slightly weakened at high temperature, but strengthened at elevated pressure. We calculated the isobaric ( iP) and isothermal ( iT) mode Grüneisen parameters for these olivine samples. The intrinsic anharmonic parameters (a i) are in negative for both the lattice and internal vibrations, and our calculations indicate that the intrinsic anharmonicity makes positive contributions to the thermodynamic properties of olivine at high temperatures, such as the internal energy (U), heat capacities (C V and C P) and entropy (S). Iron incorporation further increases the magnitudes of these anharmonic contributions. In addition, the Fe effect on the intrinsic anharmonicity may also apply to other thermodynamic properties in olivine, such as equations of state and equilibrium isotopic fractionations, which are relevant and important to constrain many physical and chemical properties in the upper mantle. This is the peer-reviewed, final accepted version for American Mineralogist, published by the Mineralogical Society of America. The published version is subject to change. Cite as Authors (Year) Title. American Mineralogist, in press.

show abstract

Section: Implicationsupporting

confidence: 57%

Section: Introductionmentioning

confidence: 93%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

High-temperature and high-pressure Raman spectra of Fo89Fa11 and Fo58Fa42 olivines: Iron effect on thermodynamic properties

Liu

Guo

Smyth

et al. 2021

American Mineralogist

View full text Add to dashboard Cite

show abstract

“…The temperature dependences of the OH-stretching modes, (∂ν i /∂T) P , for humite-group minerals are compared with other dense hydrous Mg-silicate minerals in the peridotite system (MgO-SiO 2 -Mg(OH) 2 ) ( Fig. 7), such as serpentine, brucite, talc, phases A, B, E and super hydrous phase B (Liu et al 1997a(Liu et al , 1997b(Liu et al , 1998(Liu et al , 1999(Liu et al and 2002Lin et al 1999 and2000;Zhang et al 2006;Trittschack et al 2012;Liu et al 2019a and2019b;Zhu et al 2019; this study). The OH bands above 3450 cm -1 typically show a negative temperature dependence, whereas those below 3450 cm -1 typically exhibit a positive temperature dependence.…”

Section: Oh-stretching Bands and Temperature Dependencementioning

confidence: 99%

Crystal chemistry and high-temperature vibrational spectra of humite and norbergite: Fluorine and titanium in humite-group minerals

Liu

Hirner

Smyth

et al. 2021

American Mineralogist

View full text Add to dashboard Cite

The humite-group minerals on the brucite-olivine join may be important dense hydrous magnesium silicate (DHMS) phases in the subducting slab. Fluorine and titanium can be incorporated into the crystal structures through the substitution mechanisms (OH)-= Fand Mg 2+ + 2(OH)-= Ti 4+ + 2O 2-. These substitutions have significant effects on the hydrogen bonding behavior in their crystal structures. Crystal structure refinements and in situ high-temperature Raman and Fourier transform infrared (FTIR) measurements were conducted on natural humite and norbergite crystals. Both minerals crystallize in space group Pbnm, and the isobaric Grüneisen parameters for the lattice and SiO 4 internal vibrations are compared with those of chondrodite, clinohumite, brucite and forsterite. For the humite-group minerals, the OH-stretching modes above 3450 cm-1 are affected by local H-H repulsion, whereas the behavior of those below 3450 cm-1 can be explained by Fand Ti 4+ substitutions, either of which may relieve the H-H repulsion effect. The Raman-active OH bands below 3450 cm-1 are affected by Ti 4+ substitution, while the IR-active bands can be affected by either For Ti 4+ substitutions. Based on an analysis of the high-T Raman and FTIR spectra, the OH vibrations above and below 3450 cm-1 behave differently as a function of temperature, and similar behavior has also been observed for other dense hydrous silicate phases in the hydrous peridotite system. Hence, the lengths of the oxygen-oxygen edges in MgO 6 octahedra where protonation can occur become similar to each other at elevated temperatures. This may provide an This is the peer-reviewed, final accepted version for American Mineralogist, published by the Mineralogical Society of America. The published version is subject to change. Cite as Authors (Year) Title. American Mineralogist, in press.

show abstract

“…In contrast, a minor fraction of the Mg-Rw thin section annealed at 600 • C for the cumulated annealing time of 30 min may have transited to forsterite, as indicated by the tiny new Raman peak at ~857 cm −1 . Nevertheless, the infrared spectrum 1589-06-03 (Figure 10f), probing both the surface material and the interior material of the thin section, show water peaks completely different to those of forsterite [84][85][86][87], implying a totally negligible amount of phase transition. For the purpose of comparison, the IR spectrum collected for each thin section before the annealing experiments is also shown at the bottom of each graph.…”

Section: Ir Features Of Water In Mg-rw Annealed At Different T: a Sum...mentioning

confidence: 99%

IR Features of Hydrous Mg2SiO4-Ringwoodite, Unannealed and Annealed at 200–600 °C and 1 atm, with Implications to Hydrogen Defects and Water-Coupled Cation Disorder

et al. 2020

View full text Add to dashboard Cite

Three batches of Mg2SiO4-ringwoodites (Mg-Rw) with different water contents (CH2O = ~1019(238), 5500(229) and 16,307(1219) ppm) were synthesized by using conventional high-P experimental techniques. Thirteen thin sections with different thicknesses (~14–113 μm) were prepared from them and examined for water-related IR peaks using unpolarized infrared spectra at ambient P-T conditions, leading to the observation of 15 IR peaks at ~3682, 3407, 3348, 3278, 3100, 2849, 2660, 2556, 2448, 1352, 1347, 1307, 1282, 1194 and 1186 cm−1. These IR peaks suggest multiple types of hydrogen defects in hydrous Mg-Rw. We have attributed the IR peaks at ~3680, 3650–3000 and 3000–2000 cm−1, respectively, to the hydrogen defects [VSi(OH)4], [VMg(OH)2MgSiSiMg] and [VMg(OH)2]. Combining these IR features with the chemical characteristics of hydrous Rw, we have revealed that the hydrogen defects [VMg(OH)2MgSiSiMg] are dominant in hydrous Rw at high P-T conditions, and the defects [VSi(OH)4] and [VMg(OH)2] play negligible roles. Extensive IR measurements were performed on seven thin sections annealed for several times at T of 200–600 °C and quickly quenched to room T. They display many significant variations, including an absorption enhancement of the peak at ~3680 cm−1, two new peaks occurring at ~3510 and 3461 cm−1, remarkable intensifications of the peaks at ~3405 and 3345 cm−1 and significant absorption reductions of the peaks at ~2500 cm−1. These phenomena imply significant hydrogen migration among different crystallographic sites and rearrangement of the O-H dipoles in hydrous Mg-Rw at high T. From the IR spectra obtained for hydrous Rw both unannealed and annealed at high T, we further infer that substantial amounts of cation disorder should be present in hydrous Rw at the P-T conditions of the mantle transition zone, as required by the formation of the hydrogen defects [VMg(OH)2MgSiSiMg]. The Mg-Si disorder may have very large effects on the physical and chemical properties of Rw, as exampled by its disproportional effects on the unit-cell volume and thermal expansivity.

show abstract

In Situ Infrared Spectra for Hydrous Forsterite up to 1243 K: Hydration Effect on Thermodynamic Properties

Cited by 5 publications

References 70 publications

High-temperature and high-pressure Raman spectra of Fo89Fa11 and Fo58Fa42 olivines: Iron effect on thermodynamic properties

High-temperature and high-pressure Raman spectra of Fo89Fa11 and Fo58Fa42 olivines: Iron effect on thermodynamic properties

Crystal chemistry and high-temperature vibrational spectra of humite and norbergite: Fluorine and titanium in humite-group minerals

IR Features of Hydrous Mg2SiO4-Ringwoodite, Unannealed and Annealed at 200–600 °C and 1 atm, with Implications to Hydrogen Defects and Water-Coupled Cation Disorder

Contact Info

Product

Resources

About