The correlation of structure and electronic properties near the surface of transition metal oxides

The strong couplings between different degrees of freedom are believed to be responsible for novel and complex phenomena discovered in transition metal oxides (TMOs). The physical complexity is directly responsible for their tunability. Creating surfaces/interfaces add an additional ' man-made' twist, approaching the quantum phenomena of correlated materials. ^ The dissertation focused on the structural and electronic properties in proximity of surface of three prototype TMO compounds by using three complementary techniques: scanning tunneling microscopy, angle-resolved photoelectron spectroscopy and low energy electron diffraction, particularly emphasized the effects of broken symmetry and imperfections like defects on the coupling between charge and lattice degrees of freedom. ^ Ca1.5Sr0.5RuO4 is a layered ruthenate with square lattice and at the boundary of magnetic/orbital instability in Ca2-xSrxRuO4. That the substitution of Sr 2+ with Ca2+ causing RuO6 rotation narrows the dxy band width and changes the Fermi surface topology. Particularly, the γ(dxy) Fermi surface sheet exhibited hole-like in Ca1.5Sr0.5RuO4 in contrast to electron-like in Sr2RuO4, showing a strong charge-lattice coupling. ^ Na0.75CoO2 is a layered cobaltite with triangular lattice exhibiting extraordinary thermoelectric properties. The well-ordered CoO2-terminated surface with random Na distribution was observed. However, lattice constants of the surface are smaller than that in bulk. The surface density of states (DOS) showed strong temperature dependence. Especially, an unusual shift of the minimum DOS occurs below 230 K, clearly indicating a local charging effect on the surface. ^ Cd2Re2O7 is the first known pyrochlore oxide superconductor (Tc ∼ 1K). It exhibited an unusual second-order phase transition occurring at TS1 = 200 K and a controversial first-order transition at TS2 = 120 K. While bulk properties display large anomalies at TS1 but rather subtle and sample-dependent changes at TS2, the surface DOS near the EF show no change at T s1 but a substantial increase below TS2---a complete reversal as the signature for the transitions. We argued that crystal imperfections, mainly defects, which were considerably enhanced at the surface, resulted in the transition at TS2. ^

Simply Genre Films: Extracting “King Lear” from “House of Strangers” and “Broken Lance"

The purpose of this thesis is to evaluate and refute Yvonne Griggs’ claims that the films “House of Strangers” (1949) and “Broken Lance” (1954) are as Griggs deems “genre-based adaptations” of William Shakespeare’s “King Lear.” I argue that the films, although they have some essential elements of “King Lear,” lack intentionality and reception, pivotal components in determining viability as a Shakespearean film adaptation. Using Griggs’ book as my critical background, I will show that these films are better classified under their respective genre categories, Western and film noir, not as “King Lear” genre adaptations. I will also suggest criteria for determining the level of canonicity of a “King Lear” film adaptation. Popularity of films does not determine validity, and a film does not need purported Shakespearean provenance to validate its ratings. Some films, like these, merely reference or pay homage to Shakespeare through use of essential elements of “King Lear”; here, I deem such affinities to be more unintentional than intentional.

Tagged tree broken as result of Hurricane Wilma, Shark River Slough

This material is based upon work supported by the National Science Foundation through the Florida Coastal Everglades Long-Term Ecological Research program under Cooperative Agreements #DBI-0620409 and #DEB-9910514. This image is made available for non-commercial or educational use only.

The Broken Mirror: Maternal Agency and Identity in Charles Dickens's Bleak House

This paper examined how Esther Summerson, Dickens’s ideal good mother, can be understood as a woman who has maternal agency and identity both as a character and as a narrator, and how she contrasts with other maternal characters in the novel, both major and minor. While more transgressive mothers, such as Lady Dedlock, Mrs. Jellyby and even Krook’s cat, are doomed to death, ineffectiveness and madness, Esther moves from a frozen, “unsexualized” state into a space of life and sexual possibility. In addition, Esther has agency and identity as a narrator since she shares the narration with a third-person male narrator. Esther becomes the one who speaks rather than the one who is spoken of, and her maternal, nurturing voice provides a balm for the often harsh, judgmental voice of the male narrator. As the narrator’s patriarchal voice dies away at the end, it is Esther’s maternal voice that survives.