Hydrothermal preparation and magnetic properties of NaFeSi2O6: nanowires vs bulk samples

A single-step hydrothermal route to the preparation of the pyroxene mineral, NaFeSi2O6, is reported. The as-prepared samples are found to adopt a nanowire morphology and can be made with a yield of several hundred milligrams at a time with high purity. Synchrotron X-ray diffraction, electron microscopy, and Mössbauer spectroscopy are employed to characterize the structure and morphology. A comparison of the temperature- and field-dependent magnetic properties between the nanowire and sintered phases shows substantial differences that can likely be attributed to the reduced particle size and increased number of spins on the surface of the nanowires.