This study reports a self-assembled multiferroic nanostructure, composed of PbTiO 3 (PTO) pillars embedded in a CoFe 2 O 4 (CFO) matrix, deposited on MgO(001) by pulsed laser deposition. The epitaxial relationship in the PTO-CFO nanostructure is ð100Þ½101 PTO k ð001Þ½101 CFO k ð001Þ ½101 MgO , confirming the in-plane aligned polarization of PTO. The perpendicular magnetic anisotropy of this thin film results from the magnetoelastic anisotropy that exceeds the shape anisotropy. The increased frequency and the enhanced intensity of the tetrahedral (T-) site phonon modes by increasing the magnetic field indicate strong magnetoelastic coupling through magnetostriction in this multiferroic nanostructure. The anisotropic Raman strength enhancement of the T-site phonon along different directions suggests the magnetoelastic coupling is most efficient in the in-plane direction. V

Conducting atomic force microscopy and scanning surface-potential microscopy have been applied to image the surfaces of Mg-In-codoped GaN films grown by low-pressure metal-organic chemical-vapor deposition. Biscyclopentadienylmagnesium ͑CP 2 Mg͒ and trimethylindium ͑TMIn͒ have been used as the codoping sources in the experiment. The dislocation density at the film surface reduces to the lowest level ͑ϳ1.0ϫ 10 9 cm −2 ͒ when the TMIn/ CP 2 Mg flow rate ratio is about 1. The dislocation density tends to rise when the flow ratio increases, and carriers of the film accumulate near the rim of the dislocation at an accelerated speed. The work function of dislocation is also found lower than that of nondislocation areas. Such electrical unevenness may seriously influence the light emission of the component, which should not be ignored during fabrication and deserves careful attention.

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