Nanoscale Infrared Imaging Analysis of Carbonaceous Chondrites to Understand Organic-Mineral Interactions During Aqueous Alteration

Organic matter in carbonaceous chondrites is distributed in fine-grained matrix. To understand pre- and postaccretion history of organic matter and its association with surrounding minerals, microscopic techniques are mandatory. Infrared (IR) spectroscopy is a useful technique, but the spatial resolution of IR is limited to a few micrometers, due to the diffraction limit. In this study, we applied the high spatial resolution IR imaging method to CM2 carbonaceous chondrites Murchison and Bells, which is based on an atomic force microscopy (AFM) with its tip detecting thermal expansion of a sample resulting from absorption of infrared radiation. We confirmed that this technique permits 30 nm spatial resolution organic analysis for the meteorite samples. The IR imaging results are consistent with the previously reported association of organic matter and phyllosilicates, but our results are at much higher spatial resolution. This observation of heterogeneous distributions of the functional groups of organic matter revealed its association with minerals at 30 nm spatial resolution in meteorite samples by IR spectroscopy

カト カイセツ コウシホウ ニ ヨル タンパクシツ フォールディング カテイ ニ オケル タンパクシツ ヨウバイカン ソウゴ サヨウ ノ ソクテイ

京都大学0048新制・課程博士博士(理学)甲第13361号理博第3202号新制||理||1475(附属図書館)UT51-2007-Q762京都大学大学院理学研究科化学専攻(主査)教授 寺嶋 正秀, 教授 竹腰 清乃理, 教授 谷村 吉隆学位規則第4条第1項該当Doctor of ScienceKyoto UniversityDA