Our neighbor Thomas Gredig related his research on phthalocyanines especially as a thin film for its potential as an organic solar-cell material and also to exploit the magnetic properties of this versatile compound.
Thomas pointed out that phthalocyanines were originally developed as a relatively inexpensive blue dye, and its applications have evolved into a variety of directions including optical, electrical, chemical, as well as magnetic. The compound thus finds use in synthetic metals, organic electronics, small sensors, and photodynamic therapies, to name a few. His group has discovered that these molecules are ferromagnetic and has found ways to control and characterize the magnetism by changing deposition temperatures to control crystal size.
Magnetic interactions play a significant role in many modern applications. The magnetic properties of many alloys have been characterized and studied in depth showing a broad array of interesting phenomena, which include the hardness, coercivity, saturation magnetization, and critical behavior near the transition point. Rather than finding new properties through exploring new materials, Thomas and his group of students have shown that properties of the material can be designed. For that purpose, they use a single chain magnet, called iron phthalocyanine, to form iron chains of different length, oriented in different directions. The iron chains are embedded in a carbon matrix and self-assemble on the substrate, when deposited via thermal evaporation. They show that through design—tuning the length of the chain—properties, such as the coercivity, and magnetic relaxation can be selected. This system can have long magnetic relaxation times, where the remanent moment slowly decays. Their results can be compared to findings from spin-glasses.
Thomas has one more year left on a very prestigious 5-year National Science Foundation CAREER Award.
In another sucessful and parallel physics-education-research PER direction, Thomas has been funded by the Chancelor's Office to develop a homework and study website to facilitate online learning forums for students currently enrolled in introductory physics at CSULB.
Thomas, thank you for the informative visit and sharing your varied research interests with us!