Phase transitions and proton ordering in hemimorphite: new insights from single-crystal EPR experiments and DFT calculations

Mao, Mao; Li, Zucheng; Pan, Yuanming

doi:10.1007/s00269-012-0553-5

Cited by 3 publications

(2 citation statements)

References 37 publications

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“…The three corners of the tetrahedron are bonded together and form a six-atomic ring (2Zn + Si + 3O), which is connected with each other on the (010) surface to form an unlimited extension of the layer. The electronic structure of the ore was calculated via DFT [15,16], and the optimized crystal cell model is shown in Figure 2.…”

Section: Methodsmentioning

confidence: 99%

Basic Characteristics of Hemimorphite and Its Transformation Mechanism with Na2CO3

et al. 2018

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The crystal of hemimorphite is a non-conductor. The Si-O bond in the crystal is strong, whereas the Zn-O bond is weak. These properties lead to the easy breakage of the Zn-O bond in the crushing process of hemimorphite. Thus, the interaction between minerals and polar water molecules is strong, and natural floatability of ores is poor. This study systematically investigated the characteristics of hemimorphite and its action mechanism with Na 2 CO 3. Results of SEM-EDS showed that the surface of hemimorphite dissolved after interacting with Na 2 CO 3 , and the contents of Si and O decreased, whereas Zn and C increased. XPS analysis showed that the carbonate group was detected. The interaction between CO 3 2− and hemimorphite was calculated using the first principles calculation based on density functional theory. The results indicate that an O atom in CO 3 2− interacted with Zn 2+ from the (100) plane of hemimorphite. The interaction between Zn and O atoms was not strong, and the Zn atoms were not completely displaced, which was proven by density of state analysis and the EDS and XPS results. The Mulliken population showed that the O-Zn bond was the atomic bonding of CO 3 2− with Zn 2+ and exhibited properties of ionic bonds. Thus, hemimorphite transformed to smithsonite-like mineral (ZnCO 3) when acting with CO 3 2− .

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Section: Methodsmentioning

confidence: 99%

Basic Characteristics of Hemimorphite and Its Transformation Mechanism with Na2CO3

et al. 2018

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“…This opens the possibility of observing new types of dynamical and phase behavior. For example, hemimorphite Zn 4 Si 2 O 7 (OH) 2 •H 2 O, a natural, orthorhombic, microporous zinc silicate, contains water molecules and hydroxyl groups that form a 2D H-bond network [14][15][16][17][18][19]. The crystal framework consists of rings of corner-sharing ZnO 3 (OH) and SiO 4 tetrahedra forming pore channels in the c-direction.…”

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confidence: 99%

Fast Rotational Diffusion of Water Molecules in a 2D Hydrogen Bond Network at Cryogenic Temperatures

et al. 2018

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Individual water molecules or small clusters of water molecules contained within microporous minerals present an extreme case of confinement where the local structure of hydrogen bond networks are dramatically altered from bulk water. In the zinc silicate hemimorphite, the water molecules form a two-dimensional hydrogen bond network with hydroxyl groups in the crystal framework. Here, we present a combined experimental and theoretical study of the structure and dynamics of water molecules within this network. The water molecules undergo a continuous phase transition in their orientational configuration analogous to a two-dimensional Ising model. The incoherent dynamic structure factor reveals two thermally activated relaxation processes, one on a subpicosecond timescale and another on a 10-100 ps timescale, between 70 and 130 K. The slow process is an in-plane reorientation of the water molecule involving the breaking of hydrogen bonds with a framework that, despite the low temperatures involved, is analogous to rotational diffusion of water molecules in the bulk liquid. The fast process is a localized motion of the water molecule with no apparent analogs among known bulk or confined phases of water.

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Electron Paramagnetic Resonance Spectroscopy: Basic Principles, Experimental Techniques and Applications to Earth and Planetary Sciences

Pan¹,

Nilges²

2014

Reviews in Mineralogy and Geochemistry

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Phase transitions and proton ordering in hemimorphite: new insights from single-crystal EPR experiments and DFT calculations

Cited by 3 publications

References 37 publications

Basic Characteristics of Hemimorphite and Its Transformation Mechanism with Na2CO3

Basic Characteristics of Hemimorphite and Its Transformation Mechanism with Na2CO3

Fast Rotational Diffusion of Water Molecules in a 2D Hydrogen Bond Network at Cryogenic Temperatures

Electron Paramagnetic Resonance Spectroscopy: Basic Principles, Experimental Techniques and Applications to Earth and Planetary Sciences

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