镍锰交叉在镍铁橄榄石中的自旋行为及其对地幔热导率的影响
地球物理
2026-04-17 v1 材料科学
摘要
地球下幔热导率控制着核心-幔边界（CMB）处的热量传递，并强烈影响幔 convection。我们报告了对单晶镍铁橄榄石（MgFeO，-0.13）热导率的直接测量，该矿物是下幔中第二丰富的矿物，使用光激光快门和 X 射线自由电子激光加热装置于金刚石压力罐中进行，温度可达约2200 K，压力达130 GPa。这些实验首次提供了下幔条件下镍铁橄榄石的导热数据。在60至100 GPa、约1700 K 条件下，导热率出现显著下降，符合镍锰交叉的预期。结合我们此前对 Fe-和 Fe,Al 掺杂橄榄石（bridgmanite）的研究结果，这些数据定义了下幔导热率随压力增加至约10 W m K（接近 CMB），从而约束了幔体热通量、洞穴浮力及长期地动力学演化。
引用
@article{arxiv.2604.14183,
title = {Iron spin crossover in ferropericlase and its effect on lower-mantle thermal conductivity},
author = {Alexander F. Goncharov and Irina Chuvashova and Eric Edmund and JungFu Lin and Zena Younes and Nicolas Jaisle and Axel Phelipeau and Carmen Sanchez-Valle and Christoph Otzen and Clemens Prescher and Hanns-Peter Liermann and Nico Giordano and James McHardy and Karen Appel and Michal Andrzejewski and S. V. Rahul and Minxue Tang and Jolanta Sztuk-Dambietz and Thomas Michelat and Torsten Laurus and Malcolm McMahon and Mark Robertson and Rachel Husband and Efim Kolesnikov and Sebastien Merkel and Silvia Boccato and Carsten Baehtz and Guillaume Morard and Emma S. Bullock and Cornelius Strohm and Zuzana Konopkova and Ryan Stewart McWilliams},
journal= {arXiv preprint arXiv:2604.14183},
year = {2026}
}
备注
31 pages, 11 figures