Is Robert Heinlein's Starship Troopers, published in 1959 and winner of the Hugo award for Best Novel in 1960, responsible for the modern concept of "powered armor" that is such a standard of recent science fiction movies, literature and games?
Starship Troopers is influential in popularising the idea, but it's nowhere near the origin point for the concept of powered armor.
A quick glance at Wikipedia indicates that the concept of powered exoskeletons well predates Heinlein: the first prototypes were developed in the 1890s and 1910s. The idea of using a powered exoskeleton for armor was already prevalent in science fiction like the Lensman series in the 1930s.
However, one of the scientists working on exosuit technology in the 1980s was partly inspired (though only AFTER having begun his project, so Heinlein still can't take any credit for the idea itself) by Starship Troopers.