The acquisition of a powder X-ray diffractometer (XRD) system serves a variety of research and teaching needs at UC Merced, the new 10th campus in the UC system, which officially opened its doors for undergraduate and graduate students in Fall 2005. Powder XRD is an essential tool for ongoing environmental and materials research, and a critical instrument for the expansion of our interdisciplinary materials science and engineering and chemical sciences programs. We are purchasing a basic, high quality instrument with automated capabilities that can be easily reconfigured for different applications to serve a range of users and research demands. Features of the instrument include a solid-state X-ray generator with Cu X-ray tube, theta-theta goniometer (for a stationary sample, moving source and detector), fast solid-state detector with low background, and a temperature-controlled, inert gas sample chamber attachment (-193 C to +450 C) for air-sensitive samples and investigation of temperature-dependent phase changes. The XRD instrumentation will be openly available to users as part of our existing Imaging and Microscopy Facility, the first centralized campus recharge facility, and supported by a full-time laboratory manager who will be responsible for instrument oversight and user training. It will support faculty, graduate, and undergraduate research, and it will be used in courses such as environmental chemistry, instrumental/analytical methods, soil chemistry, materials science, and materials engineering. Current and planned research that will be supported at UC Merced includes: the chemistry and mobility of contaminants in the environment; environmental chemistry and mineralogy of geoparticles in soils, sedimentary environments, and engineered systems; atmospheric and environmental agglomerates and nanoparticles; properties of natural biomaterials; synthesis, characterization, structure, and properties of semiconductor nanoparticles. Main applications include qualitative and quantitative phase identification, amorphous/crystalline characterization, polymorph discrimination, impurity analysis, and temperature- and atmosphere-dependent phase transformation studies. The instrumentation will have a broad impact in contributing to UC Merced's mission to serve the rapidly growing population of the southern Central Valley of California, which is dominantly Hispanic, has a high immigrant and first-generation population, and is historically underrepresented in higher education.