Spectroscopic properties of photorefractiveBaTiO3double doped with cerium and rhodium

Abstract

We have grown and characterized crystals of BaTiO 3 double doped with Ce and Rh. This material has defect charge states that can easily be manipulated by illumination with different wavelengths of light and may have potential for nonvolatile holographic storage using a two-step, sensitized recording scheme. Electron paramagnetic resonance ͑EPR͒, photo-EPR, optical absorption, and light-induced optical-absorption measurements were used to identify the charge states, probe the electronic structure, and locate the ionization levels associated with the Ce and Rh centers relative to the band edges of the BaTiO 3 host. In addition, the effects of illumination at various wavelengths on the defect states were used to develop a qualitative sensitization model.

Critical exponents for the ferromagnetism in colossal magnetoresistance manganites

“…magnetization measurements give mean-field-like one. [5,6] It is strongly desired to solve this controversy.…”

Toward a Theory of Followership

“…Scholars who have investigated the mythologization of leaders have shown the gap between close followers' perception of their leaders and the narrative adopted by the public. For example, Schwartz (2000), in a comprehensive study of the transformation of Abraham Lincoln into the most revered leader in American history, pointed out that Lincoln was the subject of controversy during his presidency and was then quite forgotten for some 40 years. Schwartz analyzed the development of the reverence for Lincoln as a leader, which began only in the 20th century, and he determined that this reverence was based on the conversion of Lincoln into a narrative representing the aspirations of broad populations.…”

“…Stories were spread and received through a wide variety of communication channels. For example, eight major publications featured numerous stories about Lincoln in order to promote the progressive agenda to which they were committed (Schwartz, 2000). Similarly, many politicians at the beginning of the 20th century used the figure of Lincoln as a role model (see, e.g., the speeches of President Woodrow Wilson in 1917).…”

Microstructure and Photoluminescence Properties of Mg‐Doped BaTiO3:Pr3+ Phosphor

“…E arly studies have indicated that ceramic materials with high dielectric constants have been in demand for insulators in dynamic random access memories, capacitors, and various other applications. BaTiO 3 ceramics with high dielectric and electro‐optic properties 1,2 have been thoroughly investigated for a variety of optoelectronic applications, for example, low‐loss waveguides 3 and holographic data storage 4 …”

“…BaTiO 3 ceramics with high dielectric and electrooptic properties 1,2 have been thoroughly investigated for a variety of optoelectronic applications, for example, low-loss waveguides 3 and holographic data storage. 4 In the past few years, oxide perovskite (BaTiO 3 , CaTiO 3 , and SrTiO 3 ) materials doped with trivalent praseodymium have been the subject of many investigations for field emission display phosphors. 5,6 The red emissions from SrTiO 3 :Pr 31 ( 1 D 2 -3 H 4 emission of Pr 31 ) are intensified 4200 times under UV light excitation by the addition of Al 31 in the starting materials.…”