## Nanomaterials and Spectroscopy Seminar by Dr. Valter Sergo and Dr. Vanni Lughi of University of Trieste

Dr. Valter Sergo (left) and Dr. Vanni Lughi (right) of University of Trieste

The Department of Physics of the School of Science and Engineering would like to invite you to a seminar on Nanomaterials and Spectroscopy to be held on 04 June 2018, 10:30 a.m. at Faura Hall Room 106. The seminar consists of two talks:

• “Nanoparticles and nanostructured materials for energy applications” by Vanni Lughi, Assistant professor of Materials, University of Trieste
• “Raman spectroscopy and surface-enhaced Raman spectroscopy as biomedical tools: Fundamentals and applications” by Valter Sergo, Full Professor of Materials Science and Chemistry at the University of Trieste

Below are the abstracts of the talks and the profiles of the speakers.

I. Nanoparticles and nanostructured materials for energy applications

Abstract. Nanoparticles can be thought as tailorable building blocks for fabricating new materials with on-demand, tunable properties–for example by assembling them in a controlled way. The final properties of the material will depend on the mesoscale architecture of the assembly as well as on the characteristics of the nanoparticles. I will review existing approaches and some of our laboratory’s efforts for designing and realizing engineered nanoparticle architectures (“engineering nanoparticles”), as well as for utilizing them to fabricate new materials for applications in photovoltaics and biomedical-related fields (“engineering ‘with’ nanoparticles”).

About the Speaker.  Vanni Lughi is an assistant professor of materials at the University of Trieste, and holds the national academic qualification (“abilitazione”) as associate professor. He received PhD and MS degrees in Materials from the University of California at Santa Barbara, where he worked on functional thin films and coatings. His current research and teaching activity at the nanoMaterials & Energy Laboratory (naME Lab) focuses on nanostructured materials for energy-related applications, such as for photovoltaic cells. Recently, he started researching more systemic and interdisciplinary aspects of photovoltaic systems and renewable energy sources. Over the past few years he has led or participated in a number of energy-related projects funded by public institutions as well as private companies.

II. Raman spectroscopy and surface-enhaced Raman spectroscopy as biomedical tools: Fundamentals and applications

Abstract. In recent years the use of Raman spectroscopy and Surface-Enhanced Raman Spectroscopy (SERS) for biomedical applications has been growing considerably. Intrinsically, the Raman effect is label-free and, as such, it does not introduce unwanted guests in the system under analysis. In a label-free Raman SERS approach, analytes (drugs, biomarkers, etc.) are put in contact with nanostructured metallic surfaces, (typically Au or Ag nanoparticles with suitable optical properties) generating a complex spectrum very rich in information. This fact, coupled with the rapidity of measurements and the ease of sample preparation, have paved the way for a wide spread use of these techniques in materials science, life sciences, and in medicine. In this talk an introduction to the Raman and SERS effect will be presented; then the schematic of the equipment will be outlined and then some practical case histories will be discussed: (a) Localization of hemozoin inside single red blood cells infected with malaria (Plasmodium falciparum), (b) Aging of zirconium oxide leading to catastrophic failure of ceramic hip joint prostheses, (c) Raman Mapping of the cartilage tissues and calcified cardiac valves, (d) Nanotechnologies and Raman SERS applied to quantification of low-concentration chemotherapics, and (e) Nanotechnologies, Raman SERS, and statistical analysis for screening of prostate and breast cancer.

About the Speaker. Valter Sergo is a Full Professor of Materials Science and Chemistry at the University of Trieste (Italy). He has published over 100 scientific papers, mostly in materials science and Raman spectroscopy. He has been a research associate at the University of California at Santa Barbara, at the Kyoto Institute of Technology (Japan) and has been visiting professor at the Technical University of Dresden (Germany). In the last ten years his main research focus has been on the development of medical optical diagnostic tools based on Raman spectroscopy. Presently he is one of the five Working Group leaders of the official European COST action RAMAN4CLINICS, devoted to the introduction of Raman spectroscopy in clinical practice and the member officially representing Italy in the management committee of the same EU project.

## Ateneo Physics faculty Artoni Ang went to a two-week internship at NAIST

by Quirino Sugon Jr.

Artoni Ang setting up of the UHV SEM for Auger Electron Spectroscopy

Artoni Ang, an Assistant Instructor and a graduate student of the Department of Physics of Ateneo de Manila University, went to Narra Institute of Technology (NAIST) last October 2012 for a two-week internship.  NAIST is a graduate school for Material Science, Information Science and Biological Sciences in Nara, Japan. Since 2006, it has been holding the NAIST Project for Interns (NAPI) where qualified students from the Ateneo de Manila University are invited to the laboratory of their choice for a 2 week internship.  For his internship, Artoni went to the Surface and Materials Laboratory under Professor Hiroshi Daimon.  This laboratory focuses on the study of nanomaterials, surfaces, and interfaces using the 10 m long Ultra High Vacuum (UHV) total analysis system developed by the laboratory.

Below is an interview of Artoni by the Ateneo Physics News:

1. How long have you been teaching in Ateneo?

Less than a year.  This is my second semester. I am teaching Ps 1 and 2 (Natural Science course) and various lab classes for Health Science and Biology majors. I am teaching 13 units this semester.

2.  Where do you do your research in Ateneo?

I work in Mr. Ivan Culaba’s Vacuum Coating Laboratory at the first floor of Faura Hall. Right now I am working on thin films on elastomeric substrates. I am trying to make stretchable diffraction grating. Specifically, I wish to reduce the cracking on the metal film as the grating is stretched. Metal films on stretchable substrates have many applications.  Diffraction gratings are just one of them.  Diffraction gratings are surfaces with very fine line grooves like furrows in a field, except that the distance between furrows is in the order of the wavelength of light, which is a few hundred nanometers or a fraction of the width of a hair strand.  Reducing cracking of the grating would increase the lifetime of such material.  I am working on the optical properties of materials by using the grating as a beam scanner. If we have a beam incident to the grating, we can change the angle of the of the reflected beam by stretching the grating. Stretching would change of the grating pitch or the distance between the line grooves.

3.  How is your work in the lab related to your work in the NAIST laboratory?

It is not exactly related but similar . Here we work with thin films with thickness levels in the nanometer and micrometer range in the wavelength of light. In NAIST we work with even thinner films in the Angstrom level or about 10 layers of atoms thick. Here we have high vacuum systems with pressures of $10^{-5}$ torr. In NAIST they have ultra high vacuum high systems of $10^{-10}$ torr. Most of the procedures in running the equipment are the same, except when the pressures reach $10^{-10}$: they have to bake the chambers. They wrap the chambers with heating blankets and bake the chambers for a month to get it to $10^{-10}$ torr. In our case to reach $10^{-5}$ torr, we only need 2 hours to pump it down. We use rotary pump and oil diffusion pump. In NAIST they use turbo molecular pumps and titanium sublimation pumps. After they bake their chambers they leave it at that pressure range. Then they leave all their pumps turned on 24 hours a day. In our case, we shut the system down once we are done with a specific experiment. We don’t need to keep it turned it overnight, because we can regain the same pressure the next day after 2 hours.

The panel that controls the substrate holders in their UHV system

3.  How many interns were from Ateneo?

There were 10 of us: 1 from Biology, 4 from Materials Science, and 5 from Information Science. I am part of the Material Science group. We were all assigned to different labs. We only see each other during scheduled trips or if we run into each other during the day. I am on my own from 9:00 a.m. to 5:00 p.m.

4.  What was your day like in the NAIST laboratory?

During my first day there, they held a welcoming tea party for me. So all of the grad students and most of the pofessors were there. I get to meet everyone. Since they were around 20 of them, I can’ t remember all their names. They opened the dried mangoes I brought. They all liked it. It wasn’t a formal Japanese tea ceremony.

I was there for 2 weeks. But lab work was only about 8 days. The usual day starts with me going to the laboratory at around 9:00 a.m, though I usually try to arrive a bit later. I don’t like to be the first one in the laboratory alone. And I stay outside to wait for a graduate student to arrive. They actually they told me where they hide the key, but I am not comfortable going inside without them. My day actually starts around 10:00 a.m. I waste an hour waiting outside.

Their lab is divided into two main parts: experimental section and the offices. In my  first day they assigned  me to an empty desk. And that is where I stay. In my first day, too, I met with one of the professors: Sakura Takeda-sensei. She created a schedule for me so that I will be working with different students with their own research projects. When working with them, they perform their experiments and explain the details to me. And in some cases. I get hands-on. In one particular case, we were working for two days on a scanning tunneling microscope. But it was repair and maintenance duties. We have to remove some of the main components. It was a long job. I think they finished all the maintenance work a few days before I left. And they started baking it. I guess they had to wait a month before they can even start using it.

I was assigned to do analysis on the data we collected in the experiments. I did image processing on diffraction patterns from RHEED (Reflection High Energy Electron Diffraction) experiments. I analyzed the data collected using ARPES (Angle Resolved Photoelectron Spectroscopy). From that data we were able to obtain the electron band structure of the Lead monolayer on Germanium. I was  suppose to get the mass of heavy hole from that data, but I did not get to finish the calculations. They had their own software which came with equipment. And there was another software that I think one of the graduate students wrote using java. It just converts the data collected from ARPES to electron band diagram we are all familiar with.

I worked with another student doing RHEED experiments on Indium monolayer on Silicon substrates. I also used the Scanning Electron Microscopes on Iron polycrystalline sample. I was suppose to help on the experiment involving Bismuth on Silicon, but one of the major gauges broke down, so we have to stop.

I attended study sessions, a laboratory meeting, and a laboratory colloquium. In the study session, we spent around an hour discussing theoretical principles behind ARPES. In the colloquium, we spent the entire morning listening to two graduate students presenting papers relevant to their work. It would have been were more interesting if they were reporting in English, but they were speaking in Japanese. I sat there the entire morning looking at their slides. In the afternoon is the colloquium where every graduate student presented a slide or two about their progress since the last lab meeting. Some of the students were presenting slides whose only progress is that  they attended courses or studied their exam. Nevertheless, they still have to present those because it is apart of their process. There are also students who made a lot of progress. They presented a lot of the data they were collecting. They also made me present a brief overview of the research that I do in the Philippines. I had to leave after 4 hours. I think their meeting lasted 6 hours–the whole afternoon. Between the colloquium and laboratory meeting is lunch break. And there is 30 minutes of general laboratory cleanup.  Everybody cleans by sweeping or mopping the floors.

During the first week my sensei gave me a lot of books. After 5:00 p.m. , I usually go straight to the dorm and read the books–not the entire book but only the selected chapters. I think she was surprised that I can read them overnight, because she is just used that her students have difficulty reading books in English. So from their point of view, I read really fast.

A group photo with the professors and students of the Surface and Material Science Laboratory

5.  What do you like best during your stay in Japan?

Their transportation system is very organized. If the train is scheduled to arrive at 8:02 a.m., it will actually arrive at 8:02 a.m..  So if we go out for dinner or cultural trip, our entire travel itinerary was already arranged, because they know the schedules of the trains and buses. It was easy getting around even without a car.  And this was in Narra which is not one of the big urbanized area. But despite that the transportation system is very good. In fact when you go out to the gate of NAIST, the first thing that you see is a rice field and it smells like a rice field. But then there is a bus station in front of the gate.  So even if it is in the rural part of Narra, we can still get around. We can also actually walk to the closest train station, but it takes 40 minutes.

It seems very safe there. There were times we walked to the train station in the middle of the night beside the big mall at around 10 or 11 p.m. We were not worried about being held up. The sense of security is also visible in the campus itself. They don’t have a close gate. It is just an open road that goes toward the campus. I don’t see any security guard walking around.

Of course the food was great. The organizers brought us to Japanese restaurants. We got to try sushi, yakiniku, okonomiyaki, ramen, and some other Japanese foods. Before I went there, I promised myself that I will never say no. I will eat whatever served to me. Half of what I ate there, I don’t know what it was. And then we had weekend trips to Kyoto, Osaka, and Narra. We got to visit some of the old temples and an aquarium in Osaka. During our last day there, they took us to the shopping district in Osaka,where they sold everything from electronics to anime things to clothes.

6.  Any parting thoughts?

Overall it was a good experience. You get to see how research is done in universities in other countries. The research culture is very different. Most of the students are full-time researchers. They don’t attend courses. They only worry about their research projects. They spend an entire day in the lab, because they have a desk there. They are really focused on what they are doing in the lab. Unlike in my experience as a student, my attention is divided in the courses I am taking and the research I am doing. Of course, it would be easier if you are only focused on research work.

It was also eye-opening to me to see how disciplined the Japanese people are.  After eating in the cafeteria, they clean up. We don’t see people littering. They all follow traffic rules, unlike here in the Philippines where traffic is very chaotic.

After I finish my Masters degree, I plan to apply for Ph.D. degree outside the Philippines. I am now looking at Erasmus Mundus program for Materials Science. I have already informed my Professors in NAIST that I will be applying there, too. Hopefully, I get accepted to one of them. If not , I shall also apply to universities in the United States.