Elastic anomalies and anelastic dissipation mechanisms associated with phase transitions in minerals.

与矿物相变相关的弹性异常和滞弹性耗散机制。

• 批准号: NE/F017081/1
• 负责人: Michael Carpenter
• 金额: $ 46.05万
• 依托单位: University of Cambridge
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2009
• 资助国家: 英国
• 起止时间: 2009 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FF017081%2F1
• 关键词: Elastic; anomalies; anelastic; dissipation; mechanisms

The elastic properties of minerals have long been investigated for their relevance to the seismic properties of the earth. Interest has largely focussed on discontinuities associated with changes in mineral assemblages and these have led to our present understanding of the layered nature of the mantle and core. It has been recognised, however, that almost any change in the structure of a mineral can give rise to changes in elastic constants and that, for structural transitions driven by displacements of atoms, magnetic ordering and electronic effects, changes in elastic constants can give be as much as tens of percent. Substantial improvements in geophysical methods have also allowed attenuation effects to be investigated more systematically, and a number of models of the variation in attenuation with depth have recently been published. The present project will contribute to this new direction by providing fundamental information on the diversity of mechanisms by which attenuation can occur. The specific focus is on elastic and dissipative processes associated with phase transitions in minerals and their synthetic analogues. The objectives of the project are (a) to measure elastic constants and attenuation parameters for selected oxides and silicates in situ at high and low temperatures using Resonant Ultrasound Spectroscopy (RUS), (b) to test the influence of frequency and applied stress on dissipation phenomena, and (c) to develop further the RUS facility in Cambridge for measurements of highly dissipating samples and for iron bearing minerals at high temperatures.

矿物的弹性性质与地球的地震性质的关系一直被研究。人们的兴趣主要集中在与矿物组合变化相关的不连续性上，这些导致我们目前对地幔和地核的分层性质的了解。然而，人们已经认识到，矿物结构的几乎任何变化都会引起弹性常数的变化，对于由原子位移、磁有序和电子效应驱动的结构转变，弹性常数的变化可能高达百分之几十。地球物理方法的重大改进也使人们能够更系统地研究衰减效应，最近发表了一些衰减随深度变化的模型。本项目将通过提供有关衰减机制多样性的基本信息，为这一新方向作出贡献。具体重点是弹性和耗散过程与矿物及其合成类似物的相变。该项目的目标是：（a）使用共振超声光谱仪（罗斯）在高温和低温下测量选定氧化物和硅酸盐的弹性常数和衰减参数，（B）测试频率和外加应力对耗散现象的影响，以及（c）进一步发展位于剑桥的罗斯设施，用于测量高温下的高耗散样品和含铁矿物。

项目成果

Polar precursor ordering in BaTiO3 detected by resonant piezoelectric spectroscopy

• DOI: 10.1063/1.4823576
• 发表时间: 2013-09-30
• 期刊: APPLIED PHYSICS LETTERS
• 影响因子: 4
• 作者: Aktas, Oktay;Carpenter, Michael A.;Salje, Ekhard K. H.
• 通讯作者: Salje, Ekhard K. H.

Ferroelectric precursor behavior in PbSc 0.5 Ta 0.5 O 3 detected by field-induced resonant piezoelectric spectroscopy

场致谐振压电光谱检测 PbSc 0.5 Ta 0.5 O 3 中的铁电前驱体行为

• DOI: 10.1103/physrevb.88.174112
• 发表时间: 2013
• 期刊: Physical Review B
• 影响因子: 3.7
• 作者: Aktas O

Static and dynamic strain relaxation associated with the paraelectric-antiferroelectric phase transition in PbZrO3

• DOI: 10.1016/j.jallcom.2021.162804
• 发表时间: 2021-11
• 期刊: Journal of Alloys and Compounds
• 影响因子: 6.2
• 作者: M. A. Carpenter;E. Salje;M. B. Costa;A. Majchrowski;K. Roleder

Elastic anomalies due to structural phase transitions in mechanoluminescent SrAl2O4:Eu

• DOI: 10.1063/1.3269723
• 发表时间: 2010-01
• 期刊: Journal of Applied Physics
• 影响因子: 3.2
• 作者: M. Carpenter;C. Howard;M. J. Andrew;R. E. McKnight;Yun Liu;R. Withers

Elastic softening of leucite and the lack of polar domain boundaries

白榴石的弹性软化和缺乏极性域边界

• DOI: 10.2138/am-2015-5313ccby
• 发表时间: 2015
• 期刊: American Mineralogist
• 影响因子: 3.1
• 作者: Aktas O