Breaking Symmetry to Induce Novel Properties in Inorganic Materials

Efrain E. Rodriguez

Dept. of Chemistry and Biochemistry, University of Maryland, College Park, MD 20742

When materials break symmetry, we can observe extraordinary and novel macroscopic properties. In this seminar, I will focus on two categories of materials we design and synthesize: non-centrosymmetric metal chalcogenides as quantum materials and transition metal phosphates as ferrotoroidics. The first category broadly encompasses superconductors and magnetic materials. In this seminar I will cover layered transition metal chalcogenides intercalated by a variety of species that control the functionality of the quantum material. Our design strategy is to stack metal chalcogenide layers using molecular complexes to break their inversion symmetry and induce a non-centrosymmetric structure. For the second category of materials, I will discuss our efforts to use polarized neutron diffraction to study a class of materials that can simultaneously break space inversion and time reversal symmetries. Such materials are termed ferrotoroidic materials and they comprise the fourth ferroic category along with ferromagnets, ferroelectrics, and ferroelastics. We study how the magnetic point group symmetry of candidate antiferromagnets allows for the long-range and spontaneous order of toroidal moments.