Presentation on theme: "National Science Foundation Phase Evolution in Pseudobinary Fe 3 O 4 -Fe 2 TiO 4 and Fe 2 O 3 -FeTiO 3 Solid State Synthesis Michael E. McHenry, Carnegie-Mellon."— Presentation transcript:
National Science Foundation Phase Evolution in Pseudobinary Fe 3 O 4 -Fe 2 TiO 4 and Fe 2 O 3 -FeTiO 3 Solid State Synthesis Michael E. McHenry, Carnegie-Mellon University, DMR Outcome: The Carnegie Mellon University research group determined synthesis conditions for producing two uniform (single phase pseudobinary) regions of complex titanium based magnetic (titanomagnetite, TM) solid solutions reproducing the materials found in Mars as well as Earth. As a first step, the magnetic properties have been characterized for a range compositions in this (pseudobinary) series. Impact: Results shed light on the role of these materials on terrestrial and extraterrestrial magnetic field anomalies, providing clues to the geological evolution of planets. Explanation: Titanomagnetites (TMs) (1-x)Fe 3 O 4 -xFe 2 TiO 4 in their relaxed (or remnant) state are hypothesized to contribute to planetary magnetic field anomalies. Improved synthesis procedures and support of calculated stability diagram of Fe-Ti-O system, allowed pure Ulvospinel (Fe 2 TiO 4 ) and TMs to be produced solid state synthesis routes. Ulvospinel is then sintered with magnetite in different proportions to produce TM solid solutions. Waterfall XRD patterns for TM75- 95, showing single phase solid solutions. Phase purity depends on appropriate O 2 partial pressure high energy (SPEX) milling powders to reduce diffusion length (Xinye Liu). Synthesized Samples Martian Probe: Magnetic Detector Martian Minerals Single Phase Magnetic Properties Multi-Phase Magnetic Properties Framework for studies titanomagnetie mineral’s role in the magnetic anomalies on Mars. These carry q geomagnetic history of the planet, allow for its navigation and prospecting.
National Science Foundation Phase Evolution in Pseudobinary Fe 3 O 4 -Fe 2 TiO 4 and Fe 2 O 3 -FeTiO 3 Magnetic Properties and Microstructural Evolution Michael E. McHenry, Carnegie-Mellon University, DMR K 350 K TM (x = 75-95) Magnetization Curves which have magnetic transitions in the day to night T-swing on Mars. Left: TM15, wustite in annealed samples shown in OIM imaged lath structure because of the existence of Wustite. Wustite serves to couple grains to ~200 K, a temperature within the day to night temperature swing on Mars Right: TM75 annealed sample with TiO 2 at grain boundaries, suggesting Ti cation diffusion along grain boundaries and triple points between grains. Explanation: Titanomagnetites (TMs) (1-x)Fe 3 O 4 -xFe 2 TiO 4 relaxed (or remnant) state is a strong function of temperature. The Carnegie Mellon University research group correlates T-dependent magnetic properties (above) with microstructures below to understand properties that would be observed in magnetic field sensor probes of Mars in its day to night temperature swings.
National Science Foundation Broader Impact: Collaboration between Spain’s Instituto Nacional de Tecnican Aerospacial (INTA) and Carnegie Mellon to build a functioning magnetic sensor prototype for a future mission to Mars. Jose-Luis Mesa (INTA), Whitney Schoenthal (CMU), and Marina Diaz-Michelena (INTA) in front of a display mock-up of the Martian Probe (MetNet) INTA prototype cantilever magnetic sensor measuring the remanent state of a titanomagnetite sample prepared at CMU. Phase Evolution in Pseudobinary Fe 3 O 4 -Fe 2 TiO 4 and Fe 2 O 3 -FeTiO 3 Michael E. McHenry, Carnegie-Mellon University, DMR