The thesis, defended by Dr Jackeline Narvaez Morales on February 29 2016, was entitled Flexoelectricity in Single Crystals. It was directed by ICREA Research Professor Gustau Catalán, head of the ICN2 Oxide Nanoelectronics Group, and Dr Neus Domingo, Senior Researcher from the same Group.
The School for Doctoral Studies, together with UAB Alumni, organises an event every semester for the award of PhD degrees and PhD special prizes. In November 2018, Dr. Jackeline Narvaez Morales was awarded the UAB PhD special prize for her theses “Flexoelectricity in Single Crystals” defended in 2016. The directors of the thesis were ICREA Research Prof. Gustau Catalán, head of the ICN2 Oxide Nanoelectronics Group, and Dr Neus Domingo, Senior Researcher from the same Group.
Briefly, the ICN2 award-winning study deals with flexoelectricity, which consists on the generation of a voltage when a material is bent. This effect is present in all materials regardless of their crystal structure. In the doctoral dissertation, they studied bulk and surface flexoelectricity in dielectric and semiconductor single crystals. Both mechanisms are of the same order in ordinary dielectrics and, before this work, their respective contributions were considered indistinguishable one from another.
The research in this thesis shows, for the first time, that it is possible to separate the bulk contribution from the surface one. Importantly, Dr Narvaez also discovered that this property, previously thought to be exclusive of insulating materials, is in fact also possible –and indeed much bigger- in semiconductors. This result, published in Nature, opens the exciting possibility of using semiconductor materials for electromechanical energy harvesting.
With 66 PhD programmes, the UAB is one of the leading Catalan universities in the production of theses and generates approximately a third of the doctoral theses that are defended in the Catalan university system each year. With the PhD degree and PhD special prize award ceremonies, which are held twice during the academic year (around May and November), the UAB demonstrates its appreciation for the effort and dedication of young researchers and their contribution to the generation of knowledge.