Microstructure of SrTiO3 Boundary-Layer Capacitor Material

SiTiO₃ capacitor material with indiffused Bi₂O₃ was studied using SEM, ESCA combined with Ar⁺ ion-etching, and TEM equipped with EDX. The apparent thickness of a second-phase layer observed with SEM was found to be influenced by in-depth effects. ESCA and TEM results show that only a 10- to 100-nm thick layer of second phase is present between the SrTiO₃ grains. In addition, it was found with TEM that the outer part of each grain contained Bi (at most 2 at.%), representing a diffusion layer. These results have implications for the boundary-layer model proposed to explain the dielectric properties .     

ADAPTATION, INTERTRIAL INTERVAL, AND RESPONSE TO PREFERRED AND NON-PREFERRED CHANGE.

36 MALE AND 36 FEMALE HOODED RATS WERE GIVEN AN ADAPTATION TRIAL IN A 6-CHOICE-POINT MULTIPLE-T MAZE. FOR 1/2 THE SS THE MAZE WAS BLACK ON THE ADAPTATION TRIAL AND FOR THE OTHER 1/2 THE MAZE WAS WHITE. AFTER AN INTERTRIAL INTERVAL OF EITHER 15 MIN., 4 HR., OR 24 HR., THE CORRECT PATH OR THE CULS WERE CHANGED IN BRIGHTNESS LEAVING THE REMAINDER OF THE MAZE UNCHANGED. IT WAS FOUND THAT SELECTION OR AVOIDANCE OF A GIVEN ALTERNATIVE WAS INFLUENCED BY THE CHANGE BETWEEN TRIALS FOR ALL 3 INTERTRIAL INTERVALS BUT THAT THE AMOUNT OF INCREASE OR DECREASE IN THE SELECTION OF THE CHANGED ALTERNATIVE DECREASED WITH INCREASING INTERTRIAL INTERVALS. IT WAS ALSO FOUND THAT THE SS PREFERRED A CHANGE FROM WHITE TO BLACK TO A CHANGE FROM BLACK TO WHITE. IN OTHER WORDS, ADAPTATION, TIME BETWEEN ADAPTATION AND CHANGE, AND BRIGHTNESS PREFERENCES JOINTLY DETERMINED CHOICE-POINT BEHAVIOR. THE RELEVANCE TO CERTAIN THEORIES ACCOUNTING FOR RESPONSE TO CHANGE AND NOVELTY ARE DISCUSSED BRIEFLY. (FRENCH SUMMARY) (PsycINFO Database Record (c) 2010 APA, all rights reserved)