Negative thermal expansion in the Prussian Blue analog Zn3[Fe(CN)6]2: X-ray diffraction and neutron vibrational studies

The cubic Prussian Blue (PB) analog, Zn3 [Fe(CN)6]2, has been studied by X-ray powder diffraction and inelastic neutron scattering (INS). X-ray data collected at 300 and 84 K revealed negative thermal expansion (NTE) behaviour for this material. The NTE coefficient was found to be -31.1 x 10-6 K-1. The neutron vibrational spectrum for Zn3[Fe(CN)6]2.xH2O, was studied in detail. The INS spectrum showed well-defined, well-separated bands corresponding to the stretching of and deformation modes of the Fe and Zn octahedra, all below 800 cm-1.Comment: 4 pages, 3 figure

KLEIN: A New Family of Lightweight Block Ciphers

Resource-efficient cryptographic primitives become fundamental for realizing both security and efficiency in embedded systems like RFID tags and sensor nodes. Among those primitives, lightweight block cipher plays a major role as a building block for security protocols. In this paper, we describe a new family of lightweight block ciphers named KLEIN, which is designed for resource-constrained devices such as wireless sensors and RFID tags. Compared to the related proposals, KLEIN has advantage in the software performance on legacy sensor platforms, while in the same time its hardware implementation can also be compact

Anharmonicity of flux lattices and thermal fluctuations in layered superconductors

We study elasticity of a perpendicular flux lattice in a layered superconductor with Josephson coupling between layers. We find that the energy contains ln(flux displacement) terms, so that elastic constants cannot be strictly defined. Instead we define effective elastic constants by a thermal average. The tilt modulus has terms with ln(T) which for weak fields, i.e. Josephson length smaller than the flux line spacing, lead to displacement square average proportional to T/ln(T). The expansion parameter indicates that the dominant low temperature phase transition is either layer decoupling at high fields or melting at low fields.Comment: 15 pages, 2 eps figures, Revtex, submitted to Phys. Rev. B. Sunj-class: superconductivit