Methods of forming a crystalline strontium titanate layer may include providing a substrate with a crystal enhancement surface (e.g., Pt), depositing strontium titanate by atomic layer deposition, and conducting a post-deposition anneal to crystallize the strontium titanate. Large single crystal domains may be formed, laterally extending greater distances than the thickness of the strontium titanate and demonstrating greater ordering than the underlying crystal enhancement surface provided to initiate ALD. Functional oxides, particularly perovskite complex oxides, can be heteroepitaxially deposited over the crystallized STO.

Methods of forming a crystalline strontium titanate layer may include providing a substrate with a crystal enhancement surface (e.g., Pt), depositing strontium titanate by atomic layer deposition, and conducting a post-deposition anneal to crystallize the strontium titanate. Large single crystal domains may be formed, laterally extending greater distances than the thickness of the strontium titanate and demonstrating greater ordering than the underlying crystal enhancement surface provided to initiate ALD. Functional oxides, particularly perovskite complex oxides, can be heteroepitaxially deposited over the crystallized STO.

A crystal material represented by a general formula (1):
(Gd.sub.1-x-y-zLa.sub.xME.sub.yRE.sub.z).sub.2MM.sub.2O.sub.7   (1),
where ME is at least one selected from Y, Yb, Sc, and Lu; RE is Ce or Pr; MM is at least one selected from Si and Ge; and ranges of x, y, and z are represented by the following (i): (i) 0.0≦x+y+z<1.0, 0.05≦x+z<1.0, 0.0≦y<1.0, and 0.0001≦z<0.05 (where, when RE is Ce, y=0 is an exception).

A crystal material represented by a general formula (1):
(Gd.sub.1-x-y-zLa.sub.xME.sub.yRE.sub.z).sub.2MM.sub.2O.sub.7   (1),
where ME is at least one selected from Y, Yb, Sc, and Lu; RE is Ce or Pr; MM is at least one selected from Si and Ge; and ranges of x, y, and z are represented by the following (i): (i) 0.0≦x+y+z<1.0, 0.05≦x+z<1.0, 0.0≦y<1.0, and 0.0001≦z<0.05 (where, when RE is Ce, y=0 is an exception).

A ferroelectric device comprising a substrate; a textured layer; a first electrode comprising a thin layer of metallic material having a crystal lattice structure divided into granular regions; a seed layer; the seed layer being epitaxially deposited so as to form a column-like structure on top of the granular regions of the first electrode; at least one ferroelectric material layer exhibiting spontaneous polarization epitaxially deposited on the seed layer; the ferroelectric material layer, the seed layer, and first electrode each having granular regions in which column-like structures produce a high degree of polarization normal to the growth plane and a method of making.

A ferroelectric device comprising a substrate; a textured layer; a first electrode comprising a thin layer of metallic material having a crystal lattice structure divided into granular regions; a seed layer; the seed layer being epitaxially deposited so as to form a column-like structure on top of the granular regions of the first electrode; at least one ferroelectric material layer exhibiting spontaneous polarization epitaxially deposited on the seed layer; the ferroelectric material layer, the seed layer, and first electrode each having granular regions in which column-like structures produce a high degree of polarization normal to the growth plane and a method of making.

An electro-optical waveguide modulator device includes a seed layer on a substrate, the seed layer having a first crystallographic plane aligned with a surface of the seed layer, an electro-optical channel extending in a first direction on the seed layer and having a second crystallographic plane aligned with the surface of the seed layer, an insulator layer on both sides of the electro-optical channel on the substrate in a second direction perpendicular to the first direction, an electrode barrier layer on the electro-optical channel and the insulator layer, and one or more of electrodes extending in the second direction. The seed layer and the insulator layer each comprise material having a refractive index that is lower than the electro-optical channel.

The disclosed optical lens assemblies may include a deformable optical element including a substantially transparent transducer configured to deform, and thus change at least one optical property of, the deformable optical element. At least a portion of the substantially transparent transducer may be positioned within a substantially transparent optical aperture of the optical lens assembly. Various head-mounted displays incorporating such an optical lens assembly, and methods of fabricating the same, are also disclosed.

The disclosed optical lens assemblies may include a deformable optical element including a substantially transparent transducer configured to deform, and thus change at least one optical property of, the deformable optical element. At least a portion of the substantially transparent transducer may be positioned within a substantially transparent optical aperture of the optical lens assembly. Various head-mounted displays incorporating such an optical lens assembly, and methods of fabricating the same, are also disclosed.

A method that incorporates teachings of the subject disclosure may comprise, for example, selecting a barium-strontium-titanate (BST) material, wherein the BST material has a perovskite lattice structure with at least a first lattice constant and a second lattice constant; selecting a strontium-barium-niobate (SBN) material, wherein the SBN material has a lattice structure with at least a third lattice constant and a fourth lattice constant, wherein the third lattice constant is substantially equal to the first lattice constant, and wherein the fourth lattice constant is substantially equal to the second lattice constant; and growing, on a grain boundary region of the BST material, the SBN material, wherein the growing is via self-assembly, and wherein the growing is facilitated by the third lattice constant of the SBN material being substantially equal to the first lattice constant and the fourth lattice constant of the SBN material being substantially equal to the second lattice constant. Other embodiments are disclosed.