Eutectic fibers consisting of an ordered arrangement of LiF fibrils inside a LiREF4 matrix (RE = Y, Gd) can be grown with the micro-pulling-down method at sufficiently large pulling rate exceeding 120 mm/h. The distance between individual fibrils could be scaled down to 1 µm at 300 mm/h pulling. LiF-LiYF4 has stronger tendency to form facetted eutectic colonies than LiF-LiGdF4, explained by the larger entropy of melting of the former.

Central to the idea of metamaterials is the concept of dynamic homogenization which seeks to define frequency dependent effective properties for Bloch wave propagation. Recent advances in the theory of dynamic homogenization have established the coupled form of the constitutive relation (Willis constitutive relation). This coupled form of the constitutive relation naturally emerges from ensemble averaging of the dynamic fields and automatically satisfies the dispersion relation in the case of periodic composites. Its importance is also notable due to its invariance under transformational acoustics. Here we discuss the explicit form of the effective dynamic constitutive equations. We elaborate upon the existence and emergence of coupling in the dynamic constitutive relation and further symmetries of the effective tensors.

Molecular spintronics devices (MSDs) are capable of harnessing the controllable transport and magnetic properties of molecular device elements and are highly promising candidates for revolutionizing computer logic and memory. A MSD is typically produced by placing magnetic molecule(s) between the two ferromagnetic electrodes. Recent experimental studies show that the molecules produced unprecedented strong exchange couplings between the two ferromagnets, leading to intriguing magnetic and transport properties in a MSD. Future development of MSDs will critically depend on obtaining an in-depth understanding of the molecule induced exchange coupling and its impact on MSD’s switchability and temperature stability. However, the large size of MSD systems and unsuitable device designs are the two biggest hurdles in theoretical and experimental studies of magnetic attributes produced by molecules in a MSD. This research theoretically studies the MSD by performing Monte Carlo Simulation (MCS) studies, which have the capacity to tackle large systems- such as MSD based on magnetic tunnel junction (MTJ) test bed. The MTJ based MSD has the distinctive advantage that MTJ test bed can be subjected to experimental magnetic characterizations before and after transforming it into a MSD by bridging the molecules of interest between the two metal electrodes of a MTJ. Hence the result of our MCS can be verified experimentally.