Article
Chemistry, Physical
Claudio Cazorla, Massimiliano Stengel, Jorge Iniguez, Riccardo Rurali
Summary: We predict a significant variation in heat conductivity in SrMnO3 thin films near room temperature by applying small electric and/or magnetic fields based on first-principles simulations. This is caused by a phase transition that involves large changes in both magnetization and electric polarization, resulting in a relative heat conductivity variation of about 100%. These findings are attributed to the anharmonic spin-phonon couplings that strongly influence the mean lifetime of phonons.
NPJ COMPUTATIONAL MATERIALS
(2023)
Article
Multidisciplinary Sciences
Han Hsu, Koichiro Umemoto
Summary: It is found that Fe-bearing MgO undergoes structural and spin transitions under high pressure, which can affect the physical properties of planetary interiors.
NATURE COMMUNICATIONS
(2022)
Article
Materials Science, Multidisciplinary
Qi Wang, Zezhu Zeng, Yue Chen
Summary: By constructing an accurate potential function with machine learning, the study investigates the roles of anharmonic phonon renormalization and four-phonon scattering in the thermal transport of cubic SrTiO3. The findings suggest that four-phonon scattering plays a significant role in suppressing phonon transport in the material.
Article
Geosciences, Multidisciplinary
Youyue Zhang, Takashi Yoshino, Masahiro Osako
Summary: We have measured thermal conductivity and thermal diffusivity for polycrystalline ferropericlase with different Fe contents under high pressure and high temperature conditions. The results show that even small amounts of Fe can significantly reduce the thermal conductivity of ferropericlase at low temperatures. There is a decrease in the pressure and temperature dependence with increasing Fe content. A universal equation was derived to estimate the thermal conductivity of ferropericlase under mantle conditions.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Chemistry, Multidisciplinary
Chen Li, Hao Ma, Tianyang Li, Jinghang Dai, Md Abu Jafar Rasel, Alessandro Mattoni, Ahmet Alatas, Malcolm G. Thomas, Zachary W. Rouse, Avi Shragai, Shefford P. Baker, B. J. Ramshaw, Joseph P. Feser, David B. Mitzi, Zhiting Tian
Summary: Two-dimensional hybrid organic-inorganic perovskites exhibit ultralow thermal conductivity and weak anisotropy, with unique structure contributing to small phonon lifetimes and comparable phonon group velocities. These properties can guide the design of novel hybrid materials for various applications.
Article
Chemistry, Physical
Zhoushilin Ruan, Shenlong Jiang, Qun Zhang, Yi Luo
Summary: This study presents a systematic demonstration of phononic fine-tuning in a two-dimensional lead-halide perovskite system through fluorination. The effects of fluorination on the structural distortion-induced phononic properties are investigated using ultrafast spectroscopy and temperature-dependent photoluminescence spectroscopy. The results reveal the subtle but profound impacts of fluorination on coherent phonon modes, phonon-phonon/electron-phonon interactions, and the hot-phonon bottleneck effect.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2022)
Article
Optics
Dezhong Zhang, Yunxing Fu, Hongmei Zhan, Chenyang Zhao, Xiang Gao, Chuanjiang Qin, Lixiang Wang
Summary: Emission thermal quenching is a common issue in quasi-2D perovskite emitters and greatly reduces the luminescence efficiency of PeLEDs. In this study, a passivation strategy is developed to investigate and suppress the thermal quenching, revealing the important role of defects. The defect-passivated PeLEDs achieve improved external quantum efficiency and longer operation lifetime.
LIGHT-SCIENCE & APPLICATIONS
(2022)
Article
Chemistry, Physical
V Tkac, R. Tarasenko, E. Cizmar, A. Orendacova, K. Tibenska, J. Holubova, E. Cernoskova, Z. Cernosek, M. Orendac
Summary: The investigation of 3Zn(PO3)(2)center dot 2Mn(PO3)(2) phosphate glass revealed that it does not form a spin glass state at low temperatures, while the magnetic subsystem can be approximated by S = 5/2 antiferromagnetic dimers. Furthermore, a temperature-independent process was observed at low temperatures, attributed to cross-tunneling relaxation.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Multidisciplinary Sciences
Yoshiyuki Okuda, Kenji Ohta, Yu Nishihara, Naohisa Hirao, Tatsuya Wakamatsu, Sho Suehiro, Saori Kawaguchi, Yasuo Ohishi
Summary: This study used energy-domain synchrotron Mossbauer spectroscopy measurements to investigate the electronic spin state of iron in bridgmanite samples synthesized at different pressures. The results showed a certain amount of low-spin ferric iron in bridgmanite crystallized from an ancient magma ocean, indicating the dominance of primordial bridgmanite with low-spin Fe3+ in the deeper part of an ancient lower mantle. This finding suggests a need to modify current scenarios of terrestrial mantle thermal evolution.
SCIENTIFIC REPORTS
(2021)
Article
Geosciences, Multidisciplinary
Maximilian Schulze, Georg Spiekermann
Summary: In this study, the dynamic stabilities of four-, five- and six-fold Si-O coordination polyhedra in MgSiO3 melt were investigated using ab initio molecular dynamics simulations. The results show that fivefold-coordinated silicon can accommodate structural relaxation not only at ambient pressure, but also at pressures up to that of the mantle transition zone.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Materials Science, Multidisciplinary
Junwei Che, Xiangyang Liu, Xuezhi Wang, Quan Zhang, Gongying Liang, Shengli Zhang
Summary: This study reveals the origin of glass-like low K in RETa3O9 through atomistic simulation, which is mainly due to the rattling effect of RE3+ cations and the large difference in interatomic bonding between O-RE and O-Ta. It is also found that in RETa3O9, the majority of heat is transported by diffusive modes rather than propagating modes.
Article
Geosciences, Multidisciplinary
Yang Li, Zhigang Zhang, Juan Li, Zhidong Shi, Liang Zhao
Summary: Thermal conductivity of the mantle varies with pressure and composition, and it plays a crucial role in the thermochemical evolution of the Earth's mantle. Increasing depth-dependent thermal conductivity leads to a larger core-mantle boundary heat flow and more stable thermochemical piles, while decreasing composition-dependent thermal conductivity slightly destabilizes the primordial thermochemical piles. The long-term stability of the piles decreases if the primordial mantle material is compositionally more viscous and this destabilizing effect is enhanced by decreasing composition-dependent thermal conductivity. Overall, the combined effects of depth- and composition-dependent thermal conductivity and compositional viscosity ratio significantly influence the thermochemical evolution of the mantle.
SCIENCE CHINA-EARTH SCIENCES
(2023)
Article
Chemistry, Physical
Chen Wang, Ruihuan Cheng, Yue Chen
Summary: In this study, we have conducted a comprehensive theoretical investigation on the evolution of lattice dynamics across the superionic transition of KAg3Se2 by analyzing the thermally driven current fluctuations. We found that diffuson-like phonons induced by the strong anharmonicity of the Ag sublattice dominate thermal transport below the superionic transition, leading to nearly temperature-independent ultralow thermal conductivity in the normal ordered state. Our results provide new insights into the complex atomic dynamics of superionic conductors.
CHEMISTRY OF MATERIALS
(2023)
Article
Materials Science, Ceramics
Yunpeng Zheng, Mingchu Zou, Wenyu Zhang, Di Yi, Jinle Lan, Ce-Wen Nan, Yuan-Hua Lin
Summary: High-entropy strategy and defect engineering were used to significantly suppress thermal conductivity and optimize electrical conductivity in SrTiO3-based thermoelectric ceramics. The minimum thermal conductivity in high-entropy TiO3 bulks can be reduced to 1.17 W/(m • K), with a power factor of 295μW/(m • K-2), and a ZT value of 0.2 at 873K.
JOURNAL OF ADVANCED CERAMICS
(2021)
Article
Physics, Multidisciplinary
Lokanath Patra, Bolin Liao
Summary: Materials with a large magnetocaloric response are highly desirable. This study investigates the lattice contribution to the magnetocaloric effect in bcc iron and hcp gadolinium, and suggests that long-range indirect RKKY-type exchange leads to a larger lattice contribution to the magnetocaloric entropy change.
PHYSICAL REVIEW LETTERS
(2023)
Article
Geochemistry & Geophysics
Manuele Faccenda, Ana M. G. Ferreira, Nicola Tisato, Carolina Lithgow-Bertelloni, Lars Stixrude, Giorgio Pennacchioni
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2019)
Article
Geosciences, Multidisciplinary
James Braithwaite, Lars Stixrude
GEOPHYSICAL RESEARCH LETTERS
(2019)
Article
Chemistry, Multidisciplinary
Aaron R. Finney, Sebastien Lectez, Colin L. Freeman, John H. Harding, Stephen Stackhouse
CHEMISTRY-A EUROPEAN JOURNAL
(2019)
Article
Geochemistry & Geophysics
A. L. Edgington, L. Vocadlo, L. Stixrude, I. G. Wood, D. P. Dobson, E. Holmstrom
EARTH AND PLANETARY SCIENCE LETTERS
(2019)
Article
Multidisciplinary Sciences
Lars Stixrude, Roberto Scipioni, Michael P. Desjarlais
NATURE COMMUNICATIONS
(2020)
Article
Multidisciplinary Sciences
Federico Grasselli, Lars Stixrude, Stefano Baroni
NATURE COMMUNICATIONS
(2020)
Article
Geosciences, Multidisciplinary
Jie Deng, Lars Stixrude
Summary: The study combined the Green-Kubo method with machine learning potential to determine the thermal conductivity of a silicate liquid and found that it increases with compression and remains nearly constant on isochoric heating. The pressure dependence is due to the increasing bulk modulus on compression, while the weak temperature dependence is due to the saturation of the phonon mean free path caused by structural disorder.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Geochemistry & Geophysics
Lars Stixrude, Carolina Lithgow-Bertelloni
Summary: Exact expressions for thermal expansivity, heat capacity, and bulk modulus were derived, applicable to assemblies with arbitrary numbers of components and phases. Results were illustrated in specific systems and models, revealing the importance of phase buoyancy parameter in the mantle.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2022)
Article
Geochemistry & Geophysics
Juliane Dannberg, Rene Gassmoller, Ranpeng Li, Carolina Lithgow-Bertelloni, Lars Stixrude
Summary: Phase transitions play a crucial role in mantle convection, affecting the style and evolution of the mantle. Developing new numerical methods can more accurately model the influence of phase transitions on mantle convection, with the thickness of the phase transitions having a significant impact on the style of convection.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2022)
Article
Geosciences, Multidisciplinary
James Braithwaite, Lars Stixrude
Summary: The density contrast between crystals and coexisting liquids is important in the study of magma ocean evolution. This study used molecular dynamics simulations and spin-polarized density functional theory to investigate the behavior of iron in liquid and crystalline (Mg,Fe)O. The results showed that iron is strongly incompatible with a distribution coefficient less than 0.3 over the mantle pressure range.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Geochemistry & Geophysics
Vernon F. Cormier, Carolina Lithgow-Bertelloni, Lars Stixrude, Yingcai Zheng
Summary: Stochastic tomography is a technique that uses dense deployments of seismic sensors to identify phase changes in Earth's mantle over depth intervals. By inverting spatial coherences of amplitudes and travel times of body waves, the depth and dependence of the spatial spectrum of seismic velocity can be determined. This spectrum is then interpreted using thermodynamic stability predictions and the metamorphic temperature derivative of seismic velocities as a proxy for heterogeneity induced by phase changes in the mantle. The results of applying this technique to seismic arrays in the western US are consistent with the known history of plate subduction beneath North America.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2023)
Article
Environmental Sciences
Jiaqi Li, Thomas P. Ferrand, Tong Zhou, Jeroen Ritsema, Lars Stixrude, Min Chen
Summary: The 410-km discontinuity in the mantle transition zone is caused by the phase transformation of olivine to wadsleyite. Dense seismic arrays have revealed triplicated P-waves and provided insights into the structure of the Pacific slab near the 410-km discontinuity beneath the Sea of Japan. A low-velocity layer with reduced grain size, possibly containing unstable minerals, has been found within the cold Pacific slab near the 410-km discontinuity.
COMMUNICATIONS EARTH & ENVIRONMENT
(2023)
Article
Astronomy & Astrophysics
Lars Stixrude, Stefano Baroni, Federico Grasselli
Summary: The origin of the low luminosity and internal tidal dissipation of Uranus remains unknown. Recent experiments suggest that Uranus has high viscosity and a growing frozen core, which explains its low heat flow. The study also predicts time-varying tidal dissipation and provides testable predictions for future space missions.
PLANETARY SCIENCE JOURNAL
(2021)
Article
Geosciences, Multidisciplinary
Junjie Dong, Rebecca A. Fischer, Lars P. Stixrude, Carolina R. Lithgow-Bertelloni
Summary: This study explores the water content in Earth's mantle, finding that the mantle water storage capacity is temperature-dependent and providing estimated values. It also discusses how the volume of early oceans may have affected sea level during the early Archean, suggesting the possibility of larger surface oceans under certain conditions.
Article
Geochemistry & Geophysics
Lars Stixrude, Carolina Lithgow-Bertelloni
Summary: This study provides exact expressions for the thermal expansivity, heat capacity and bulk modulus for multi-component multi-phase systems, and demonstrates the results in simple systems and mantle composition models. By deriving a new phase buoyancy parameter expression, regions in the mantle with larger phase buoyancy parameters compared to common phase transitions were identified.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2021)
Article
Geochemistry & Geophysics
Lingyu Zhang, Kristoffer Szilas
Summary: This study presents new petrological and geochemical data for the Narssaq Ultramafic Body (NUB) in the Itsaq Gneiss Complex of SW Greenland. The results indicate that the ultramafic rocks of NUB are not mantle residues, but instead represent crustal cumulates derived from high-Mg magmas.
EARTH AND PLANETARY SCIENCE LETTERS
(2024)
Article
Geochemistry & Geophysics
Rong Xu, Sarah Lambart, Oliver Nebel, Ming Li, Zhongjie Bai, Junbo Zhang, Ganglan Zhang, Jianfeng Gao, Hong Zhong, Yongsheng Liu
Summary: This study investigated the iron isotope compositions of Cenozoic basalts in Southeast China, finding significant variations related to different types of basalts and their respective sources.
EARTH AND PLANETARY SCIENCE LETTERS
(2024)
Article
Geochemistry & Geophysics
C. J. Ebinger, Miriam C. Reiss, Ian Bastow, Mary M. Karanja
Summary: The East African rift system is formed above mantle upwellings and the formation of rifts is related to lithospheric thinning and magmatic activity. The amount of splitting varies spatially and the fast axes are predominantly parallel to the orientation of the rifts. Thick lithospheric modules have less splitting and different orientations, which may indicate mantle plume flow. Splitting rotates and increases in strength as it enters the rift zones, suggesting that the anisotropy is mainly present at shallow depths.
EARTH AND PLANETARY SCIENCE LETTERS
(2024)
Correction
Geochemistry & Geophysics
Ekaterina Rojas-Kolomiets, Owen Jensen, Michael Bizimis, Gene Yogodzinski, Lukas Ackerman
EARTH AND PLANETARY SCIENCE LETTERS
(2024)
Article
Geochemistry & Geophysics
Robert W. Nicklas, Igor S. Puchtel, Ethan F. Baxter
Summary: Oxygen fugacity is a fundamental parameter for understanding redox processes in igneous systems. This study compares the Fe-XANES oxybarometry method with the V-in-olivine method for evaluating fO(2) in MORB lavas. The results show that the V-in-olivine method is not applicable to samples with low MgO content, and that the majority of Archean komatiite sources have lower fO(2) than modern MORB.
EARTH AND PLANETARY SCIENCE LETTERS
(2024)
Article
Geochemistry & Geophysics
Chunfei Chen, Stephen F. Foley, Sebastian Tappe, Huange Ren, Lanping Feng, Yongsheng Liu
Summary: The volatile components CO2 and H2O play a major role in mantle melting and heterogeneity. In this study, Ca isotopes were used to trace the lithological heterogeneity in alkaline magmatic rocks. The results revealed the presence of K-richterite and carbonate components as the source of alkaline magmas with low delta 44/40Ca values. These findings highlight the importance of Ca isotopes as a robust tracer of lithological variation caused by volatiles in the Earth's upper mantle.
EARTH AND PLANETARY SCIENCE LETTERS
(2024)
Article
Geochemistry & Geophysics
Timothee Jautzy, Gilles Rixhon, Regis Braucher, Romain Delunel, Pierre G. Valla, Laurent Schmitt, Aster Team
Summary: Although the current approach to estimate catchment-wide denudation rates using only 10Be concentrations has made significant progress in geomorphology, this study argues for the inclusion of 26Al measurements and testing of steady-state assumptions in slow eroding, formerly glaciated landscapes. The study conducted measurements of both 10Be and 26Al in stream sediments from the Vosges Massif in France and found that elevation, slope, channel steepness, and precipitation were the primary factors controlling denudation rates. The study also revealed a significant relationship between the extent of past glaciation and the cosmogenic (un-)steadiness in the stream sediments.
EARTH AND PLANETARY SCIENCE LETTERS
(2024)
Article
Geochemistry & Geophysics
Erik van der Wiel, Douwe J. J. van Hinsbergen, Cedric Thieulot, Wim Spakman
Summary: Numerical models of Earth's mantle dynamics can predict the vigour and mixing of mantle flow, and the average slab sinking rates are an unexplored parameter that can provide intrinsic information on these characteristics. Through numerical experiments, it has been found that slab sinking rates are strongly correlated with mantle convection and mixing, and may explain geochemical observations from hotspot volcanoes.
EARTH AND PLANETARY SCIENCE LETTERS
(2024)
