A SIGNIFICANT fraction of the computer memory industry is at present involved in the manufacture of non-volatile memory devices1—that is, devices which retain information when power is interrupted. For such applications (and also for volatile memories), the use of capacitors constructed from ferroelectric thin films has stimulated much interest1. In such structures, information is stored in the polarization state of the ferroelectric material itself, which should in principle lead to lower power requirements, faster access time and potentially lower cost1. But the use of ferroelectrics is not without problems; the memories constructed to date have generally suffered from poor retention of stored information and degradation of performance ('fatigue') with use1–3. Here we describe the preparation and characterization of thin-film capacitors using ferroelectric materials from a large family of layered perovskite oxides, exemplified by SrBi2Ta2O9, SrBi2NbTaO9 and SrBi4Ta4O15. The structural flexibility of these materials allows their properties to be tailored so that many of the problems associated with previous ferroelectric memories are avoided. In particular, our capacitors do not show significant fatigue after 1012 switching cycles, and they exhibit good retention characteristics and low leakage currents even with films less than 100 nm thick.

Fatigue-free ferroelectric capacitors with platinum electrodes

http://meyersgroup.ucsd.edu/papers/journals/meyers 213.pdf

The onset of twinning in metals: a constitutive description

Consideration of Orowan strengthening effect in particulate-reinforced metal matrix nanocomposites: A model for predicting their yield strength

On the validity of the hall-petch relationship in nanocrystalline materials

https://apam.columbia.edu/files/seasdepts/applied-physics-and-applied-math/pdf-files/06-salk-chan.pdf

Cerium and yttrium oxide nanoparticles are neuroprotective.

This major eight-volume reference work provides the first unified treatment of an important interdisciplinary field.

Michael B. Bever

Papers

Encyclopedia of Materials Science and Engineering