New Aspects of Nanocrystal Research
- PDF / 792,942 Bytes
- 4 Pages / 612 x 792 pts (letter) Page_size
- 102 Downloads / 214 Views
New Aspects of Nanocrystal Research
Luis M. Liz-Marzán and David J. Norris, Guest Editors During a lecture on the optical properties of gold in 1857, Michael Faraday remarked that “a mere variation in the size of its particles gave rise to a variety of resultant colors.”1 Since Faraday was referring to his studies of nanometer-scale gold particles (now commonly referred to as nanocrystals), it is clear that the topic of this issue of MRS Bulletin is an old field with an important history. Indeed, the study of Faraday’s gold sols was critical for the development of several aspects of modern materials science, including how light interacts with matter and how colloids can be formed, manipulated, and controlled. However, despite this long history, interest in nanocrystals has increased dramatically during the last two decades. The primary motivation for this increased activity is still related to Faraday’s statement: control over the size of a material can lead to new properties. While this idea has long been exploited to manage chemical properties (e.g., resulting from changes in surface area), research during the last 20 years has also shown that the magnetic, optical, and electronic behaviors of a bulk material can be modified when its size approaches the nanometer scale. Thus, most of this “modern” period of nanocrystal research has focused on understanding the origin of these new properties. Accordingly, physical models are now available to explain superparamagnetism in magnetic nanocrystals, the optical behavior of metal nanocrystals, and quantum confinement in semiconductor nanocrystals. However, this issue will not focus on these now-familiar phenomena. Rather, it concentrates on very recent research efforts that use these phenomena to achieve specific properties in nanocrystals. The general goal of all of these efforts is to tailor the nanocrystals to move toward a desired
MRS BULLETIN/DECEMBER 2001
application. Since this process often requires the ability to build a device, an important issue is how to assemble nanocrystals into more complex structures. Such nanocrystal assemblies can utilize the individual or collective behavior of the nanocrystals. Therefore, one must understand possible particle interactions and how they contribute to the properties of the material. To represent these “New Aspects of Nanocrystal Research,” this issue presents six contributions. Our selection of authors was based on what we feel is the “cutting edge” in this field. All of the authors have recently made exciting contributions to nanocrystal research, and it is our aim to bring this work to the attention of a broad audience. Since a large variety of issues are explored, we have simply organized the articles according to the type of nanocrystals that are investigated, namely, magnetic, semiconducting, or metallic. The issue starts with an article by Murray et al. that focuses on the synthesis and characterization of monodisperse transitionmetal nanocrystals (Co, Ni, and Fe) and their assembly into ordered two- and three-d
Data Loading...
