Research Interest:

Synthesis and characterization of the structural and physical properties of (i) Novel relaxor-based piezo-/ferroelectric single crystals, (ii) Ferroelectrics for non-volatile random access memories (FeRAM), (iii) Crystalline oxides on Si & gate dielectrics, (iv) Magnetically ordered ferroelectric / ferroelastic materials, and (v) photovoltaic and optoelectronic materials.

Current Research Topics:

  1. Growth, by various techniques, of the innovative high strain piezoelectric single crystals belonging to the relaxor ferroelectric and ferroelectric solid solution systems: (1-x)Pb(Mg1/3Nb2/3)O3-xPbTiO3 [PMN-PT], (1-x)Pb(Zn1/3Nb2/3) O3-xPbTiO3 [PZN-PT], and (1-x)Pb(Sc1/2Nb1/2)O3-xPbTiO3 [PSN-PT], and some new solid solution systems.
  2. Crystal Growth of halide perovskites, including organic-inorganic halide perovskites and all-inorganic perovskites, APbX3 (A= CH3NH3, Cs, K, and X= I, Br, Cl), and studies of phase symmetries, domain structures, and physical properties.
  3. Synthesis of the above-mentioned materials in the forms of nanoparticles, dense ceramics and thin films by solid state reactions and chimie douce approaches.
  4. Preparation of magnetically ordered dielectric and ferroelectric crystals and thin films: REMnO3 (RE=Ho, Er, Tm, Yb Lu or Y) and MBO3 (M=Fe3+, V3+, Cr3+ and Ti3+); Investigation of their potential as gate dielectrics in Si technologies.
  5. Synthesis of ferroelectric layered perovskite SrBi2Ta2O9 [SBT] and related compounds in the forms of single crystals and ceramics; study of their anisotropic properties;
  6. Determination of nuclear and magnetic structures of the materials by (synchrotron) X-ray and neutron diffraction, with emphasis on the morphotropic phase boundary behavior and its effects on the properties.
  7. Thermoanalysis of the relaxor systems for establishment of the relevant phase diagrams.
  8. Characterization of the dielectric, piezoelectric, pyroelectric, ferroelectric and magnetoelectric properties.
  9. Investigation of the mesoscopic domain structures and their effects on the macroscopic electric and magnetic properties, and thereby the related device performance.
  10. Studies of the phase transitions as a function of temperature and the phase transitions induced by electric field, mechanical stress and magnetic field.
  11. Studies of the dielectric relaxation and critical behavior in relaxor materials by impedance spectroscopy; modeling of the microscopic origin and mechanisms of relaxor ferroelectricity; establishment of the microstructure and property relationships.
  12. Development of ferroic materials for applications of in advance technologies, such as (i) Ultrasonic probes for medical imaging, diagnosing and treatments; (ii) Electromechanical transducers for undersea communications (SONAR); (iii) Non-volatile ferroelectric random access memories (FeRAM), etc.