Coherent precipitation-hardened alloys often struggle to achieve both ultrahigh strength and exceptional ductility due to their limited resistance to dislocation motion and vulnerability to glide plane softening. Here, we tackle these challenges by introducing multicomponent precipitates with much increased antiphase boundary (APB) energy. In a model Ni ₃ Al-type (L1 ₂ ) precipitation-hardened face-centered cubic (FCC) NiCo-based alloy, we incorporate multiple elements at the Al sublattice sites within the precipitates, reducing antisite defects and enhancing ordering degree. This process yields multicomponent precipitates with an ultrahigh APB energy (~308 ± 14 millijoules per square meter), which notably strengthens the alloy. Moreover, the exceptionally high APB energy transforms the deformation mechanism from dislocation shearing to stacking fault shearing, thereby avoiding glide plane softening. These result in a tensile yield strength of 1616 ± 9 megapascals, an ultimate tensile strength of 2155 ± 22 megapascals, and a uniform elongation of 10.1 ± 0.3% for the alloy.

The switching currents and field-induced apparent tilt angles in an antiferroelectric liquid crystal, (R)-MHPOBC, were measured. The structural differences among different smectic C* subphases may sensitively reflect the field or temperature dependence of the apparent tilt angle. In a thin cell, the apparent tilt angle was found to change in two steps as a function of field strength in the SmC*alpha and SmC* phases: a steep increase at lower fields and a small linear increase at higher fields. The steep increase in apparent tilt angle is divided into two parts via a plateau in the ferrielectric SmC*gamma phase. Stepwise change with a plateau is also seen in the relation of apparent tilt angle versus temperature under various electric fields. Moreover, the apparent tilt angle in the vicinity of the plateau is almost temperature- and field-independent, implying a preferred orientation of the molecules in the ferrielectric state. The influence of the cell thickness on the structural changes was also investigated.