Structural distortions at polar manganite interfaces

Study of Oxygen Distortions in Titanate – Manganite Interfaces by Aberration Corrected STEM-EELS

Transition metal oxides constitute a most interesting family of materials thanks to the interplay between structure, electronic and orbital degrees of freedom, which are related to collective phenomena like magnetism, ferroelectricity, superconductivity, electron transfer, etc. Interfaces between complex oxide materials provide a promising scenario for novel physical phenomena to arise. The cry...

Atomic-scale compensation phenomena at polar interfaces.

The interfacial screening charge that arises to compensate electric fields of dielectric or ferroelectric thin films is now recognized as the most important factor in determining the capacitance or polarization of ultrathin ferroelectrics. Here we investigate using aberration-corrected electron microscopy and density-functional theory to show how interfaces cope with the need to terminate ferro...

Polar distortions in hydrogen-bonded organic ferroelectrics

Alessandro Stroppa,1,* Domenico Di Sante,2 Sachio Horiuchi,3,4 Yoshinori Tokura,5,6 David Vanderbilt,7 and Silvia Picozzi1 1CNR-SPIN, L’Aquila, Italy 2University of L’Aquila, Physics Department, Via Vetoio, L’Aquila, Italy 3National Institute of Advanced Industrial Science and Technology (AIST) Tsukuba, Ibaraki 305-8562, Japan 4CREST, JST, Tsukuba 305-8562, Japan 5Department of Applied Physics,...

Evolution of the band alignment at polar oxide interfaces

OFFSETS AND POLARIZATION AT STRAINED AlN/GaN POLAR INTERFACES

The strain induced by lattice mismatch at the interface is responsible for the different value of the band discontinuities observed recently for the AlN/GaN (AlN on GaN) and the GaN/AlN (GaN on AlN) polar (0001) interface. We present a first-principles calculation of valence band offsets, interface dipoles, strain-induced piezoelectric fields, relaxed geometric structure, and formation energies...