The temperature is lowered to 5 Coulomb for the gadolinium alloy Gd 85 Er 15 , and this effect is considerably stronger for the alloy Gd 5 (Si 2 Ge 2 ), but at a much lower temperature ( A significant magnetocaloric effect is observed at higher temperatures, up to about 300 kelvins, in the compounds Gd 5 (Si x Ge 1−x ) 4 .