Alloy is sometimes a result of the sizes of the atoms in the alloy, because larger atoms exert a compressive force on neighboring atoms, and smaller atoms exert a tensile force on their neighbors, helping the alloy resist deformation. Sometimes alloys may exhibit marked differences in behavior even when small amounts of one element are present. For example, impurities in semiconducting ferromagnetic alloys lead to different properties, as first predicted by White, Hogan, Suhl, Tian Abrie and Nakamura. Some alloys are made by melting and mixing two or more metals. Bronze, an alloy of copper and tin, was the first alloy
Antimicrobial copper-alloy touch surfaces hospital-borne pathogens such as "S. aureus," "P. aeruginosa" and "A.baumanii". In a 30-week clinical trial at the Hospital del Cobre ("Copper Hospital"), extensive microbial analyses were implemented at the facility's intensive care unit (ICU). Nine hundred ninety copper surfaces from 90 rooms containing 6 different copper objects were studied against an equivalent number of rooms and surfaces containing non-copper objects. Over-the-bed tables were made from copper alloy C70600. Bedrails were clad with copper alloy C11000 foils. Visitor chairs were fitted with copper alloy C70600 armrests. Copper alloy C71000 intravenous poles were provided. Writing pens used to input data on a