The chemical composition and texture of cosmic spherules are influenced by atmospheric conditions and the characteristics of their parent interplanetary particles. The objective of this study was to reproduce I‐type cosmic spherules, which consist mainly of Fe oxide and Fe‐Ni metal, and compare their textural characteristics with those of natural I‐type cosmic spherules. Thus, a series of rapid heating and quenching experiments were performed on free falling iron meteorite powders obtained from Canyon Diablo, in the United States. The experiments were conducted using a high‐temperature furnace with controlled gas flow rates at oxygen fugacities of FMQ + 2.4, FMQ, and FMQ − 2.5 log unit. The resulting Fe‐Ni metal and oxide phases showed the nonequilibrium state of the melted spherules formed during quenching. Two types of magnetite crystals in different orientations were found in iron oxide. As temperatures decreased, the molten metal was oxidized to form immiscible molten iron oxide that then covered the former. As the oxide melt increased at the expense of metal, magnetite began to crystallize from the iron oxide melt, as the liquidus phase, either on the surface or within the melt phase. The characteristics of the run products obtained under different oxygen fugacities were similar to those of natural I‐type cosmic spherules, which have textures and compositions that may contain information regarding the oxygen content of the upper atmosphere. Our study suggests that CO₂‐bearing molecules in the atmosphere could form iron oxide with a texture similar to natural I‐type cosmic spherules. During this process, rapid crystallization of magnetite plays an important role in texture formation in disequilibrium states.

中文翻译：

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I型宇宙球的复制和Fe-Ni-O系统的表征

宇宙球的化学组成和质地受大气条件及其母行星际颗粒特性的影响。这项研究的目的是复制主要由Fe氧化物和Fe-Ni金属组成的I型宇宙球，并将其结构特征与天然I型宇宙球进行比较。因此，对从美国Canyon Diablo获得的自由下落的铁陨石粉末进行了一系列快速加热和淬火实验。使用高温炉进行实验，氧气流量控制在FMQ + 2.4，FMQ和FMQ-2.5 log单位的氧气逸度下。生成的Fe-Ni金属和氧化物相显示淬火过程中形成的熔融球的非平衡态。在氧化铁中发现了两种取向不同的磁铁矿晶体。随着温度降低，熔融金属被氧化形成不混溶的熔融铁氧化物，然后覆盖前者。随着以金属为代价的氧化物熔体的增加，磁铁矿开始从氧化铁熔体中以液相相的形式结晶，在液相或熔体相内部。在不同的氧气逸度下获得的运行产物的特性与天然I型宇宙球相似，其结构和成分可能包含有关高层大气中氧含量的信息。我们的研究表明，CO 随着以金属为代价的氧化物熔体的增加，磁铁矿开始从氧化铁熔体中以液相相的形式结晶，在液相或熔体相内部。在不同的氧气逸度下获得的运行产品的特性类似于天然I型宇宙球的特性，它们的质地和成分可能包含有关高层大气中氧气含量的信息。我们的研究表明，CO 随着以金属为代价的氧化物熔体的增加，磁铁矿开始从氧化铁熔体中以液相相的形式在表面或熔体相中结晶。在不同的氧气逸度下获得的运行产品的特性类似于天然I型宇宙球的特性，它们的质地和成分可能包含有关高层大气中氧气含量的信息。我们的研究表明，CO 其质地和成分可能包含有关高层大气中氧含量的信息。我们的研究表明，CO 其质地和成分可能包含有关高层大气中氧含量的信息。我们的研究表明，CO大气中带有_2个分子的分子可能形成氧化铁，其质地类似于天然的I型宇宙球。在此过程中，磁铁矿的快速结晶在不平衡状态下的织构形成中起着重要作用。