Teach Quantum Mechanics and Physical Chemistry with STM

An Interview with Dr. James Batteas

Dr. James Batteas, chemistry professor at Texas A & M University, uses the Nanosurf® easyScan 2 Scanning Tunneling Microscope (STM) to teach Junior Physical Chemistry students the concepts of quantum mechanics and modern physical chemistry (PChem). Dr. Batteas is an innovative and highly published scientist who works extensively with an ultra-high vacuum STM to probe nanoscale surface properties. He is also equally passionate about helping students understand the concepts of quantum mechanics through PChem lectures.

STM for quantum mechanics and physical chemistry at TX A&MSTM for quantum mechanics and physical chemistry at TX A&M

His expertise in both research and teaching helped him realize that there was a distinct disconnect between the theory and the outdated laboratory experiments. He, along with other faculty members, decided to renovate and revitalize the traditional PChem labs and introduce the students to “modern” tools like the STM.

“We wanted to show our students how research is conducted in state-of-the-art facilities around the world today, not 50 years ago,” explained Dr. Batteas.

The STM was one of the instruments he chose because it is new technology and is used extensively by surface chemists and physicists everywhere. He used internal money to purchase the easyScan 2 STM and devised a series of experiments to compliment his lectures. The Nanosurf STM was the ideal candidate for his purposes because of its affordability, size, portability, ease-of-use and robustness. Dr. Batteas found the instrument to be very reliable.

Fifty undergraduate students get hands-on training during the typical 3-week lab. Experiments were adapted from a paper published by Batteas et. al. in the Journal of Physical Chemistry C, titled “Synthesis and Characterization of a Thiol-Tethered Tripyridyl Porphyrin on Au(111).” With the help of his students, Amanda Schuckman and Brad Ewers, Dr. Batteas tweaked the experiments to fit the mold of an undergraduate lab while giving them exposure to real world research projects.

"Students get acquainted with the concepts of quantum mechanics before they get a chance to go hands-on with the STM. This approach helps the students better understand what they are seeing and helps them interpret the STM data. The STM gives students an opportunity to visualize the quantum mechanical concepts they learn about in lectures.” Dr. Batteas told the NanoAdvisor.

During the lab, Dr. Batteas introduces his students to the STM by showing them how to cut tip wire to make perfect STM tips. The students shear gold wire to get an atomically sharp conductive tip which is able to image a surface by maintaining a constant tunneling current. The students then image samples like highly ordered pyrolytic graphite (HOPG) and gold. Both HOPG and gold take minimal sample preparation so students can focus on mastering the imaging technique. Dr. Batteas said that most of his students achieve single atom resolution on HOPG with the Nanosurf STM and find it very rewarding to actually visualize something they had only read about so far.

STM on bungy cords at TX A&M STM on bungy cords at TX A&M 

When imaging a gold surface, students get to see atomic steps and flat terraces on the surface which are fascinating as well. The next part of the experiment consists of tethering thiols to the gold surface and studying the electron tunneling through the adsorbed molecules. They compare results to bare gold and thereby quantify the change in electron transport due to the introduction of a barrier.

Finally, the students measure charge transfer through porphyrin molecules on gold using imaging and STM spectroscopy techniques. The students also learn how to get publication-worthy images using image processing software. Dr. Batteas makes sure that students in his undergraduate lab learn all the skills necessary to make them proficient researchers.

Dr. Batteas' work is soon to be published in the Journal of Chemical Education. Electronic transitions and charge transfer through molecules are investigated extensively in many research labs across the world because of their relevance in biological systems and organic photovoltaics. However, only a handful of dedicated professors have been able to translate a research project into an experiment fit for an undergraduate laboratory. Dr. Batteas is one such professor and his efforts give his students a head start in the world of advanced research techniques.

For more information about Dr. Batteas’ work, please contact him at james.batteas@gmail.com.