中文摘要：

通过透射电镜原位观察，发现单斜η-Al11Cr2相在800℃保温2h后，其三个主带轴电子衍射图中的超点阵弱点逐渐减弱直至消失，且a轴和c轴所成的角度由91°变为90°，这些变化意味着单斜η-Al11Cr2相在加热后转变为一个新相，点阵参数为a=1.2428nm，b≈1.2658nm，c≈3．0456nm的体心正交相，命名为O-Al11Cr2.其[010]电子衍射图具有伪十次对称特点，因此也是一个十重对称准晶近似相.

英文摘要：

Through in-situ high temperature TEM observation, the weak diffractions of the monoclinic η-Al11Cr2 were found to disappear after having been heated at 800℃ for 2 hours, and the monoclinic angle of η-Al11Cr2 changed from 91° to right angle. These changes meant Ccentered monoclinic η-Al11Cr2 had transformed into a new orthorhombic O-Al11Cr2 with a = 1.2428 nm, b = 1.2658 nm, c = 3.0456 nm. This is the first time that orthorhombic O phase is found in Al-Cr binary alloys, though it has ever been found in many other related Al-based alloys. It is also an approximant of Al-Cr decagonal quasicrystal.