Catalyst-free synthesis and structural and mechanical characterization of single crystalline Ca2B2O5.H2O nanobelts and stacking faulted Ca2B2O5 nanogrooves.

Single crystalline Ca(2)B(2)O(5).H(2)O (CBOH) nanobelts were synthesized for the first time using a facile catalyst-free hydrothermal method at low temperature. After being annealed at 400 degrees C for 10 h, the CBOH nanobelts transformed into curve-shaped Ca(2)B(2)O(5)(CBO) nanogrooves with ordered stacking fault arrays along the [110] direction. The single crystalline CBOH nanobelts and the stacking faulted CBO nanogrooves provided a unique platform for investigating the effects of hydrated H(2)O and stacking faults on the mechanical properties of nanomaterials. Nanoindentation tests were performed directly on individual CBOH nanobelts and CBO nanogrooves to probe their mechanical properties. It was found that the CBOH nanobelts, with the presence of hydrated H(2)O, achieved 28.7% increase in elastic modulus, whereas the stacking faulted CBO nanogrooves, with the absence of hydrated H(2)O, exhibited 99% loss in elastic modulus, compared to bulk CBO.