On the permittivity of titanium dioxide.

Area of Science:

• Materials Science
• Solid State Physics
• Semiconductor Physics

Background:

• Conductive rutile titanium dioxide (TiO2) is crucial for various applications.
• Reported permittivity values for conductive TiO2 vary widely (100-10,000), causing scientific debate.

Purpose of the Study:

• To establish a reliable method for measuring permittivity in conductive, n-type TiO2.
• To resolve the controversy surrounding the permittivity of reduced or doped TiO2.

Main Methods:

• Utilized hydrogen ion-implantation to create a controlled donor concentration profile in TiO2.
• Employed capacitance-voltage (C-V) measurements for precise donor profiling and permittivity determination.

Main Results:

• The study refutes claims of extremely high permittivity in single crystalline TiO2.
• Permittivity of conductive, reduced single crystalline TiO2 was measured to be 160-240 along the c-axis.
• Observed a Curie-Weiss type temperature dependence, consistent with insulating TiO2.

Conclusions:

• The permittivity of conductive, reduced single crystalline TiO2 is comparable to its insulating counterpart.
• The developed measurement technique provides a more accurate assessment of TiO2 permittivity.
• Disputed extremely high permittivity values, establishing a narrower, more reliable range.