TOPICS OF RESEARCH

Physics on Ferroelectrics

「Light Spectroscopy」

Angle-resolved Raman spectroscopy equipment was established. Now we can assign (local) modes as well as estimate the Raman tensors quantitatively.

「Materials Design」

We fabricate ferroelectric, piezoelectric, and dielectric materials with various method.
For crystal growth, FZ method, flux method, Bridgman method, top-seed method are used.
For ceramics fabrication, Spark-Plasma-Sintering, convntional technique are used.
Many furnaces are in our Lab.

The crystals above are KF-BaTiO3 crystals, which show favorable piezoelectricity for transducers.

「Physics related with ferroelectrics」

Anormalous annealing effect was discovered in our laboratory as shown in the following figure: TC increases as much as 100 K with annealing.
We also discovered ferroelectricity in BaTi2O5.
We are looking for something new everyday.

A dielectric constant of over 100 000, with dielectric loss of less than 0.1, was found in 1.0 mol. % Ni-doped KTaO3 (KT:1%Ni) single crystals, showing temperature and frequency stabilities favorable for capacitor applications. We also consider ferroelectric materials from a viewpoint of the application.