Nano-grain thin films

J.A. Poirier, G.E. Stoner, Microstructural effects on electronic oxygen reduction activity of nano-grained thin-film platinum in acid media. J. Electrochem. Soc. 1994, 141(2), 425 30. 

Jahn-Teller Effects in Nano-Grain Thin Films... 

As an example, result from a test sample is presented in Figure 6. A nano-crystalline thin film sample was prepared by vacuum evaporation of 100 A NiO and 100 A Al. The thicknesses were controlled by quartz thickness measurement. The proportion of phases was also checked by EDS. TEM BF and DF pictures show that the grain size of NiO is around 4 nm. 

Figure 8.8. The zero-field resistivity of powder samples of Lao.ssCao.asMnOs are highly dependent on the grain size. (After Fontcuberta et al. (1999), Nano-Crystalline and Thin Film Magnetic Oxides. Nedkov and Ausloos (eds.) Kluwer Academic Publishers. Reproduced with permission.)...

In these studies, yttria-stabilized zirconia (YSZ) thin films, NiO-i-YSZ cermet, and modified Lao.rSro.jMnOj (LSM) perovskite were used as electrolyte, anode and cathode, respectively. The details of the single cell preparation can be found elsewhere [7]. Specially, Ceo,gSmo,202-6 nano-grains were introduced to porous LSM backbone via a wet infiltration method to improve the cell performance in methane-oxygen mixture [7]. 

O.K. VARGHESE, L. MALHOTRA, Electrode sample capacitance effect on ethanol sensitivity of nano-grained Sn02 thin films . Sensors and Actuators, B 53,1998. 

Sometimes large differences are encountered between the microhardness of bulk material and thin films. This is most probably due to the different dislocation density and the grain size of both types of materials. Also the difference in testing (micro- or nano-indentation for films, heavier load up to several N for bulk samples) most probably yield differences. In addition, the composition (as for any of the properties discussed here) influences the microhardness. Because of these peculiarities the values are difficult to compare. 

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