The gmr effect has became a international researching hotspot after the discovery of gmr effect of fe / cr multilayers . people found that multilayers formed by ferromagnetic metal of transition family and nonmagnetic metal or by alloy film and nonmagnetic metal will take on gmr effect . the value of gmr of co / cu multilayers is the biggest which can reach 65 % under room temperature 继fe / cr多层膜巨磁电阻效应发现以后，巨磁电阻效应已成为国际研究的热点，人们发现过渡族铁磁金属或合金薄膜与非磁性金属构成多层膜后均可呈现巨磁电阻效应，其中以co / cu多层膜的gmr值最高，室温巨磁电阻效应可达65 % 。
