Equilibrium interfaces were established between body-centered cubic (BCC) crystals and their liquid using charged colloidal particles in an electric bottle. By measuring a time series of interfacial positions and computing the average power spectrum, their interfacial stiffness was determined according to the capillary fluctuation method. For the (100) and the (114) interfaces, the stiffnesses were 0.15 and 0.18 kBT/σ2 (σ: particle diameter), respectively, and were isotropic in the plane of the interface. For comparison, similar charged colloids were used to create an interface between a face-centered cubic (FCC) crystal and its liquid. Its stiffness was significantly larger: 0.26 kBT/σ2. This result gives experimental support to the explanations offered for the preferential nucleation of BCC over FCC in metallic alloys.

使用电瓶中的带电胶体颗粒，在体心立方（BCC）晶体和其液体之间建立了平衡界面。通过测量界面位置的时间序列并计算平均功率谱，根据毛细管波动法确定了它们的界面刚度。对于（100）和（114）界面，刚度分别为0.15和0.18ķ乙Ť/σ2（σ：粒径）分别在界面平面上是各向同性的。为了进行比较，使用了类似的带电胶体在面心立方（FCC）晶体与其液体之间创建界面。其刚度明显更大：0.26ķ乙Ť/σ2。该结果为金属合金中BCC比FCC优先成核的解释提供了实验支持。