New technologies launch novel materials; besides their performances in products, their health hazards must be tested.

The catalytic chemical vapor deposition (CCVD) is currently the most flexible and economically attractive method for the growth of carbon nanotubes. Although its principle is simple, the precisely controlled growth of carbon nanotubes remains very complex because many different parameters influence the growth process. In this article, we review our recent results obtained on the synthesis of carbon nanotubes via CCVD. We discuss the role of the catalyst and the catalyst support. Our recent results obtained from the water assisted growth and the equimolar C₂H₂-CO₂ reaction are also discussed. Both procedures lead to significantly enhanced carbon nanotube growth. In particular, the latter allows growing carbon nanotubes on diverse substrate materials at low temperatures.

The demand for ever-increasing density of information storage and speed of manipulation boosts an intense search for new magnetic materials and novel ways of controlling the magnetic bit. Here, we report the synthesis of a ferromagnetic photovoltaic CH₃NH₃(Mn:Pb)I₃ material in which the photo-excited electrons rapidly melt the local magnetic order through the Ruderman–Kittel–Kasuya–Yosida interactions without heating up the spin system. Our finding offers an alternative, very simple and efficient way of optical spin control, and opens an avenue for applications in low-power, light controlling magnetic devices.

For future nanomechanical devices to be realized, sophisticated ways of manipulating small structures must be developed, and fundamental elements of macroscopic machines, such as switches and bearings, must be reproduced in the nanoscale. Forró highlights the nanotube nanobearings and nanoswitches reported by Cumings and Zettl and concludes that multiwall nanotubes are ideal starting materials for future nanodevices.