Effects of the postannealing atmosphere on the dielectric properties of (Ba, Sr)TiO3 capacitors: Evidence of an interfacial space charge layer

Abstract

The dielectric properties of (Ba, Sr)TiO3 films were found to be remarkably sensitive to the postannealing treatment atmosphere. This study demonstrates that postannealing in an oxygen atmosphere increases the dielectric relaxation phenomenon and that postannealing in a nitrogen atmosphere produces a slight dielectric relaxation. Such dependence of the dielectric relaxation was related both to oxygen vacancies and to the presence of negatively charged oxygen, trapped at the grain boundary and/or at the electrode/dielectric film interface.

Piezoelectric properties of Bi4Ti3O12 thin films annealed in different atmospheres

“…On the other hand, when the capacitor was treated in an oxygen atmosphere, the V m voltage at which the capacitance is at its maximum C m value is not located at the zero bias field, but shifted towards the positive bias region. The higher capacitance, which depends on the bias polarity, suggests that the existence of an additional capacitance at the interface arises from space charges, originating from annealing in oxygen atmosphere [10].…”

O papel dos modificadores de rede na produção da fotoluminescência no CaWO4

“…Os pós de CaWO 4 , amorfo e cristalino, foram sintetizados pelo método dos precursores poliméricos [15][16]. Este método tem sido usado, com grande sucesso, para sintetizar nanopartículas e filmes finos de vários sistemas complexos de óxidos policatiônicos.…”

“…Materiais com estas características ópticas podem apresentar estas propriedades FL [10,11]. Como no caso dos tungstatos amorfos, várias propriedades interessantes de perovsquitas têm sido relatadas, inclusive mostrando que o comprimento de onda emitido está relacionado ao comprimento de onda incidente [12][13][14][15][16].…”

Photoluminescence at room temperature in amorphous SrTiO3 thin films obtained by chemical solution deposition

“…This paper reports on measurements of broad, intense photoluminescence observed at room temperature in SrTiO 3 amorphous thin films prepared at low temperatures and obtained by the polymeric precursor method [13][14][15].…”