"contrary to the expectation" is correct and can be used in written English.
You can use this phrase to express that something came as a surprise, and was not what was anticipated. For example, "Contrary to the expectation, the results of the election turned out differently than expected."
Contrary to the expectation that the losers of elections might be more inclined to violence, the two authors determined that winning increases support for violence against the opposition.
Contrary to the expectation the conductive nanofibers do not improve the electron transport in the photoelectrodes and the solar to electrical conversion efficiency is limited to about 2.4%.
Contrary to the expectation, however, the inhibitory potency of 6 was not improved and that of 7 was rather attenuated by the replacement.
Contrary to the expectation that surviving trees have weathered severe drought, the hydraulic deterioration demonstrated here reveals that surviving regions of these forests are actually more vulnerable to future droughts due to accumulated xylem damage.
According to their analysis, local-scale factors explained about three-quarters of the variation in wood decomposition, while climate explained only about one-quarter, contrary to the expectation that climate should be the predominant control.
Yet, contrary to the expectation that revenue-neutrality would increase the political feasibility of the carbon charge by not penalizing heavy energy users, Yale found the concept to be complex and challenging to communicate.
Under sulfur-free conditions, isooctane conversion and synthesis gas yield increased as the Ni particle size increased, contrary to the expectation that smaller particle sizes with lower Ni coordination would be more active.
It was found that the plant with the bucket elevator had at least as large a change in the median particle size as the plant with the pneumatic transport system, contrary to the expectation.
The lack of consistent differences in stem borer survival and development between the NPT lines and Indica varieties was contrary to the expectation that the morphology of the NPT would render it more susceptible to stem borers.
However, contrary to the expectation, the gelation behavior could not occur in PVA/water solutions at the same condition of gelation in PVA/NMP solution even though the affinity of water to PVA is much lower than that of NMP.
The experiments carried out for three representative liquid liquid systems show that contrary to the expectation the addition of an electrolyte increases the dispersed phase fraction at which inversion occurs for both, oil-in-water and water-in-oil dispersions.
