Limits...
Scanning Probe Microscopy on heterogeneous CaCu3Ti4O12 thin films.

Fiorenza P, Lo Nigro R, Raineri V - Nanoscale Res Lett (2011)

Bottom Line: The conductive atomic force microscopy provided a local characterization of the dielectric heterogeneities in CaCu3Ti4O12 (CCTO) thin films deposited by MOCVD on IrO2 bottom electrode.In particular, both techniques have been employed to clarify the role of the inter- and sub-granular features in terms of conductive and insulating regions.The role of internal barriers and the possible explanation for the extrinsic origin of the giant dielectric response in CCTO has been evaluated.

View Article: PubMed Central - HTML - PubMed

Affiliation: Istituto per la Microelettronica e Microsistemi (IMM), Consiglio Nazionale delle Ricerche, Strada VIII, 5; 95121 Catania, Italy. patrick.fiorenza@imm.cnr.it.

ABSTRACT
The conductive atomic force microscopy provided a local characterization of the dielectric heterogeneities in CaCu3Ti4O12 (CCTO) thin films deposited by MOCVD on IrO2 bottom electrode. In particular, both techniques have been employed to clarify the role of the inter- and sub-granular features in terms of conductive and insulating regions. The microstructure and the dielectric properties of CCTO thin films have been studied and the evidence of internal barriers in CCTO thin films has been provided. The role of internal barriers and the possible explanation for the extrinsic origin of the giant dielectric response in CCTO has been evaluated.

No MeSH data available.


C-AFM current map (a) collected on CCTO thin films, I-Vs acquired in a 10 × 10 matrix and its distribution histogram
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3211163&req=5

Figure 3: C-AFM current map (a) collected on CCTO thin films, I-Vs acquired in a 10 × 10 matrix and its distribution histogram

Mentions: The nanoscale mapping of the electrical response is reported in Figure 3 at room temperature. It was carried out in order to distinguish the presence of an internal barrier [25] or a superficial polarization [26]. The current map (a) has been collected on the bare CCTO thin film surface. Insulating grain boundaries and conducting grains are clearly visible (Figure 3a). This dielectric structure recalls the CCTO ceramics considering also the BW morphology. Further details have been provided by the current versus voltage (I-V) curves, locally collected by C-AFM on a 10x10 matrix points, each spaced of 200 nm. The I-V curves clearly belong to two families as reported in the related histogram (Figure 3b). The first family is centred at high current values and the second at quite lower current values. They can be respectively related to the current flowing through the grain (when the tip is statistically contacting a grain) or the grain boundaries (when the tip is occasionally contacting the grain boundaries). The current flowing through the grain boundaries is at least two orders of magnitude lower than in the grains as already observed in CCTO polycrystalline ceramics [27].


Scanning Probe Microscopy on heterogeneous CaCu3Ti4O12 thin films.

Fiorenza P, Lo Nigro R, Raineri V - Nanoscale Res Lett (2011)

C-AFM current map (a) collected on CCTO thin films, I-Vs acquired in a 10 × 10 matrix and its distribution histogram
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3211163&req=5

Figure 3: C-AFM current map (a) collected on CCTO thin films, I-Vs acquired in a 10 × 10 matrix and its distribution histogram
Mentions: The nanoscale mapping of the electrical response is reported in Figure 3 at room temperature. It was carried out in order to distinguish the presence of an internal barrier [25] or a superficial polarization [26]. The current map (a) has been collected on the bare CCTO thin film surface. Insulating grain boundaries and conducting grains are clearly visible (Figure 3a). This dielectric structure recalls the CCTO ceramics considering also the BW morphology. Further details have been provided by the current versus voltage (I-V) curves, locally collected by C-AFM on a 10x10 matrix points, each spaced of 200 nm. The I-V curves clearly belong to two families as reported in the related histogram (Figure 3b). The first family is centred at high current values and the second at quite lower current values. They can be respectively related to the current flowing through the grain (when the tip is statistically contacting a grain) or the grain boundaries (when the tip is occasionally contacting the grain boundaries). The current flowing through the grain boundaries is at least two orders of magnitude lower than in the grains as already observed in CCTO polycrystalline ceramics [27].

Bottom Line: The conductive atomic force microscopy provided a local characterization of the dielectric heterogeneities in CaCu3Ti4O12 (CCTO) thin films deposited by MOCVD on IrO2 bottom electrode.In particular, both techniques have been employed to clarify the role of the inter- and sub-granular features in terms of conductive and insulating regions.The role of internal barriers and the possible explanation for the extrinsic origin of the giant dielectric response in CCTO has been evaluated.

View Article: PubMed Central - HTML - PubMed

Affiliation: Istituto per la Microelettronica e Microsistemi (IMM), Consiglio Nazionale delle Ricerche, Strada VIII, 5; 95121 Catania, Italy. patrick.fiorenza@imm.cnr.it.

ABSTRACT
The conductive atomic force microscopy provided a local characterization of the dielectric heterogeneities in CaCu3Ti4O12 (CCTO) thin films deposited by MOCVD on IrO2 bottom electrode. In particular, both techniques have been employed to clarify the role of the inter- and sub-granular features in terms of conductive and insulating regions. The microstructure and the dielectric properties of CCTO thin films have been studied and the evidence of internal barriers in CCTO thin films has been provided. The role of internal barriers and the possible explanation for the extrinsic origin of the giant dielectric response in CCTO has been evaluated.

No MeSH data available.