A cross-correlation analysis between different parameters of the solar wind plasma based on Voyager 1 and 2 data from 1 to 9.5 AU evidences, as a predominant feature of the microscale structure of the solar wind, a persistent presence of time periods characterized by high anticorrelation between the magnetic field magnitude and the proton density. These events are present at least 25% of the total time, and their frequency of occurrence progressively increases with increasing heliocentric distance. These results have been satisfactorily interpreted as being due to the presence of nonpropagating structures with internal pressure balance and characteristic time scale of ≲10 hours. Alfv¿nic fluctuations are confirmed to dominate the microscale at 1--2 AU, but they seem to become less important at larger heliocentric distances. ¿American Geophysical Union 1987