Lithium Tantalite Research Articles

Pyroelectric properties of sol–gel derived lithium tantalite thin films

Lithium tantalite (LiTaO 3) thin films (∼0.5 μm) have been successfully deposited on Pt(111)/ SiO 2/ Si(1 0 0) substrates by means of sol–gel spin-coating technology. Figures of merit for infrared detector were studied for the LiTaO 3 thin films. There exists high figures of merit F v of 2.1×10 −10 C cm/J and F m of 2.4×10 −8 C cm/J because of the relative low dielectric constant ( ε r) of 35 and high pyroelectric coefficient ( γ) of 4.0×10 −8 C/cm 2 K of the films. The pyroelectric infrared detector fabricated by the LiTaO 3 thin film exhibits a voltage reponsivity R v of 4584 V/W at 20 Hz and a high specific detectivity D ∗ of 4.23×10 7 cm Hz 1/2/ W at 100 Hz .

A polarization‐independent athermal electro‐optic bulk modulator using a unique sandwich configuration

AbstractIn this paper, a unique polarization‐independent athermal electro‐optic modulator using lithium niobate (LiNbO3) and/or lithium tantalite (LiTaO3) crystals is presented. The modulator uses a unique sandwich configuration, in which a pair of lithium niobate crystals are bonded together and an embedded electrode is sandwiched in between them. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 36: 157–160, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10707

Tbit/inch 2 ferroelectric data storage based on scanning nonlinear dielectric microscopy

Nanosized inverted domain dots in ferroelectric materials have potential applications in ultrahigh-density rewritable data storage systems. Here, a data storage system based on scanning nonlinear dielectric microscopy and thin films of ferroelectric single-crystal lithium tantalite is presented. Through domain engineering, nanosized inverted domain dots have been successfully formed at a data density of 1.50 Tbit/in.2.

Properties of LiTaO3 Thin Films Derived by a Diol-Based Sol–Gel Process

Lithium tantalite (LiTaO3) thin films have been successfully deposited on Pt(111)/SiO2/Si(100) substrates by means of sol–gel spin-coating technology. The XRD results show that the LiTaO3 thin films heated at temperatures higher than 700°C exhibit randomly oriented polycrystalline. The relative dielectric constant (εr) increases from 35 to 300 at temperature ranging from 30 to 610°C, then decreases as the temperature increases above 610°C. The dielectric loss factor (tan δ) is as low as 0.006 at temperatures ranging from 30 to 770°C. For the first time, the ferroelectric properties of LiTaO3 thin films (∼0.5 µm) deposited on Pt(111)/SiO2/Si(100) substrates have been investigated. The sample shows a phase transition at 610°C, a coercive field (Ec) of 22.3 kV/cm, a remnant polarization (Pr) of 2.4 µC/cm2 and a maximum pyroelectric coefficient (γ) of 4.0×10-8 C/cm2·K at 62°C. The high figures of merit (FV and Fm of 2.1×10-10 C·cm/J and 2.4 ×10-8 C·cm/J, respectively) of LiTaO3 films reveal that a good infrared response of this LiTaO3 thin film can be utilized in its application to detectors.

Phase transition and the soft lattice mode of a perovskite crystal studied by Raman scattering and thermal measurements

The paraelectric–ferroelectric structural transition of potassium lithium tantalite niobate has been studied by both Raman scattering and thermal measurements. A condensed soft lattice vibrational mode at the phase transition has been analyzed. It originates from the symmetric O2/O3–Nb/Ta–O3/O2 in-plane bending of the Nb/TaO6group. The soft optical phonon mode concerns the extraordinary transverse optical phonons propagating along the [110] direction. The thermal expansion experiments show a displacive phase transition and a big thermal contraction in thecdirection of the crystal, with an average linear expansion coefficient αc= −4.52 × 10−5K−1. The phase transition temperature and enthalpy are 358 K and 0.50 J/g, respectively. Curie temperature measured by four methods is within 353 and 360 K.