Detail Size-Driven Structural and Thermodynamic Complexity in Iron Oxides   Oleh:  Navrotsky, Alexandra ; Mazeina, Lena ; Majzlan, Juraj Jenis: Article from Bulletin/Magazine Dalam koleksi: SCIENCE (keterangan: ada di Proquest) vol. 319 no. 5870 (Mar. 2008), page 1635-1638. Topik: Size-Driven Structural; Thermodynamic Complexity; Iron Oxides Ketersediaan Perpustakaan FK Nomor Panggil: S01.K.2008.03 Non-tandon: 1 (dapat dipinjam: 0) Tandon: tidak ada     Lihat Detail Induk Isi artikel Iron oxides occur ubiquitously in environmental, geological, planetary, and technological settings. They exist in a rich variety of structures and hydration states. They are commonly fine-grained (nanophase) and poorly crystalline. This review summarizes recently measured thermodynamic data on their formation and surface energies. These data are essential for calculating the thermodynamic stability fields of the various iron oxide and oxyhydroxide phases and understanding their occurrence in natural and anthropogenic environments. The competition between surface enthalpy and the energetics of phase transformation leads to the general conclusion that polymorphs metastable as micrometer-sized or larger crystals can often be thermodynamically stabilized at the nanoscale. Such size-driven crossovers in stability help to explain patterns of occurrence of different iron oxides in nature. Opini Anda Klik untuk menuliskan opini Anda tentang koleksi ini! Kembali

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