scholarly journals Electronic Spin Transition of Iron in the Earth's Deep Mantle

Eos ◽  
2007 ◽  
Vol 88 (2) ◽  
pp. 13 ◽  
Author(s):  
Jung-Fu Lin ◽  
Steven D. Jacobsen ◽  
Renata M. Wentzcovitch
Keyword(s):  
Spin Transition ◽  
Electronic Spin ◽  
Deep Mantle

scholarly journals Phase Stability and Vibrational Properties of Iron-Bearing Carbonates at High Pressure

Minerals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1142
Author(s):  
Chaoshuai Zhao ◽  
Liangxu Xu ◽  
Weibin Gui ◽  
Jin Liu
Keyword(s):  
High Pressure ◽  
Phase Transitions ◽  
Spin Transition ◽  
Laser Raman ◽  
Electronic Spin ◽  
Pressure Medium ◽  
Raman Modes ◽  
Sample Chamber ◽  
The Stability ◽  
Iron Bearing

The spin transition of iron can greatly affect the stability and various physical properties of iron-bearing carbonates at high pressure. Here, we reported laser Raman measurements on iron-bearing dolomite and siderite at high pressure and room temperature. Raman modes of siderite FeCO3 were investigated up to 75 GPa in the helium (He) pressure medium and up to 82 GPa in the NaCl pressure medium, respectively. We found that the electronic spin-paring transition of iron in siderite occurred sharply at 42–44 GPa, consistent with that in the neon (Ne) pressure medium in our previous study. This indicated that the improved hydrostaticity from Ne to He had minimal effects on the spin transition pressure. Remarkably, the spin crossover of siderite was broadened to 38–48 GPa in the NaCl pressure medium, due to the large deviatoric stress in the sample chamber. In addition, Raman modes of iron-bearing dolomite Ca1.02Mg0.76Fe0.20Mn0.02(CO3)2 were explored up to 58 GPa by using argon as a pressure medium. The sample underwent phase transitions from dolomite-Ⅰ to -Ⅰb phase at ~8 GPa, and then to -Ⅱ at ~15 and -Ⅲb phase at 36 GPa, while no spin transition was observed in iron-bearing dolomite up to 58 GPa. The incorporation of FeCO3 by 20 mol% appeared to marginally decrease the onset pressures of the three phase transitions aforementioned for pure dolomite. At 55–58 GPa, the ν1 mode shifted to a lower frequency at ~1186 cm−1, which was likely associated with the 3 + 1 coordination in dolomite-Ⅲb. These results shed new insights into the nature of iron-bearing carbonates at high pressure.

scholarly journals Electronic spin transition in FeO2 : Evidence for Fe(II) with peroxide O22−

2019 ◽  
Vol 100 (1) ◽  
Author(s):  
Bo Gyu Jang ◽  
Jin Liu ◽  
Qingyang Hu ◽  
Kristjan Haule ◽  
Ho-Kwang Mao ◽  
...  
Keyword(s):  
Spin Transition ◽  
Electronic Spin

Deformation of lower-mantle ferropericlase (Mg,Fe)O across the electronic spin transition

2009 ◽  
Vol 36 (10) ◽  
pp. 585-592 ◽  
Author(s):  
Jung-Fu Lin ◽  
Hans-Rudolf Wenk ◽  
Marco Voltolini ◽  
Sergio Speziale ◽  
Jinfu Shu ◽  
...  
Keyword(s):  
Lower Mantle ◽  
Spin Transition ◽  
Electronic Spin

scholarly journals Electronic Spin Transition in Nanosize Stoichiometric Lithium Cobalt Oxide

2012 ◽  
Vol 134 (14) ◽  
pp. 6096-6099 ◽  
Author(s):  
Danna Qian ◽  
Yoyo Hinuma ◽  
Hailong Chen ◽  
Lin-Shu Du ◽  
Kyler J. Carroll ◽  
...  
Keyword(s):  
Cobalt Oxide ◽  
Spin Transition ◽  
Lithium Cobalt Oxide ◽  
Electronic Spin ◽  
Lithium Cobalt

scholarly journals Low-spin ferric iron in primordial bridgmanite crystallized from a deep magma ocean

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yoshiyuki Okuda ◽  
Kenji Ohta ◽  
Yu Nishihara ◽  
Naohisa Hirao ◽  
Tatsuya Wakamatsu ◽  
...  
Keyword(s):  
Lower Mantle ◽  
Ferric Iron ◽  
Thermal Evolution ◽  
Spin Transition ◽  
Mantle Heterogeneity ◽  
Magma Ocean ◽  
Electronic Spin ◽  
Energy Domain ◽  
History Of ◽  
Open Question

AbstractThe crystallization of the magma ocean resulted in the present layered structure of the Earth’s mantle. An open question is the electronic spin state of iron in bridgmanite (the most abundant mineral on Earth) crystallized from a deep magma ocean, which has been neglected in the crystallization history of the entire magma ocean. Here, we performed energy-domain synchrotron Mössbauer spectroscopy measurements on two bridgmanite samples synthesized at different pressures using the same starting material (Mg0.78Fe0.13Al0.11Si0.94O3). The obtained Mössbauer spectra showed no evidence of low-spin ferric iron (Fe3+) from the bridgmanite sample synthesized at relatively low pressure of 25 gigapascals, while that directly synthesized at a higher pressure of 80 gigapascals contained a relatively large amount. This difference ought to derive from the large kinetic barrier of Fe3+ rearranging from pseudo-dodecahedral to octahedral sites with the high-spin to low-spin transition in experiments. Our results indicate a certain amount of low-spin Fe3+ in the lower mantle bridgmanite crystallized from an ancient magma ocean. We therefore conclude that primordial bridgmanite with low-spin Fe3+ dominated the deeper part of an ancient lower mantle, which would contribute to lower mantle heterogeneity preservation and call for modification of the terrestrial mantle thermal evolution scenarios.

Sign in / Sign up

Export Citation Format

Share Document