We introduce giant liposomes to investigate phase transformations in picoliter volumes. Precipitation of calcium carbonate in the confinement of DPPC liposomes leads to dramatic stabilization of amorphous calcium carbonate (ACC). In contrast, amorphous strontium carbonate (ASC) is a transient species, and BaCO3 precipitation leads directly to the formation of crystalline witherite.

For the purpose of nondestructive measurements hazardous heavy-element-containing substances in soil samples, emerging technique, triple-exposure X-ray computed tomography (CT), is proposed. The use triple exposure (i.e. three different acceleration voltages for tube) improves accuracy identification atomic number a heavy element. With lead as target element, virtual microtomography simulations...

In this study, we present the first experimental results for stable barium (Ba) isotope ((137)Ba/(134)Ba) fractionation during low-temperature formation of the anhydrous double carbonate BaMn[CO(3)](2). This investigation is part of an ongoing work on Ba fractionation in the natural barium cycle. Precipitation at a temperature of 21±1°C leads to an enrichment of the lighter Ba isotope described...

Metastable carbonates play important roles in geochemistry, biomineralization and serve as model systems for nonclassical theories of nucleation growth. Balcite (Ca0.5Ba0.5CO3) is a remarkable carbonate phase that isostructural with high-temperature modification calcite (CaCO3), yet can be synthesized at ambient conditions. Here, we investigate crystallization pathways the Ba–Ca–CO3–H2O system,...

Barium isotopes could be a novel tracer in low-temperature geochemical processes such as the Ba cycle rivers and oceans. Equilibrium isotope fractionation between Ba-hosting minerals aqueous solution is of great importance for applications geochemistry, but it remains poorly constrained. In this study, we performed first-principles calculations based on density functional theory (DFT) to determ...

Crystallisation of barium carbonate from alkaline silica solutions results in the formation of extraordinary micron-scale architectures exhibiting non-crystallographic curved shapes, such as helical filaments and worm-like braids. These so-called ‘‘silica biomorphs’’ consist of a textured assembly of uniform elongated witherite nanocrystallites, which is occasionally sheathed by a skin of amorp...