We have produced arrays of Co nanowires in anodic porous alumina filters by means of electrodeposition. The structure and magnetization behavior of the wires was investigated with nuclear magnetic resonance ͑NMR͒ and magnetization measurements. NMR shows that the wires consist of a mixture of fcc and hcp texture with the ͑0001͒ texture of the hcp fraction oriented preferentially perpendicular to the wires. The magnetization direction is determined by a competition of demagnetizing fields and dipole-dipole fields and can be tuned parallel or perpendicular to the wires by changing the length of the wires.

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Thermal expansion measurements in the range of 20–500 °C were carried out on both poly- and single crystalline samples of the hexagonal magnetoplumbite ferrite with composition BaTiFe11O19. The continuous scanning of the thermal expansion reveals the existence of a λ-type anomaly near the Curie temperature. In contrast to the usual observed anisotropic behavior for magnetoplumbite hexaferrites, the averaged thermal expansion coefficient for the a direction is larger than for the c direction, i.e., 12.8×10−6 and 9.5×10−6 °C−1, respectively.

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