20 research outputs found
Magnetic properties of PdAs2O6: a dilute spin system with an unusually high N\'eel temperature
The crystal structure and magnetic ordering pattern of PdAs2O6 were
investigated by neutron powder diffraction. While the magnetic structure of
PdAs2O6 is identical to the one of its isostructural 3d-homologue NiAs2O6, its
N\'{e}el temperature (140 K) is much higher than the one of NiAs2O6 (30 K).
This is surprising in view of the long distance and indirect exchange path
between the magnetic Pd ions. Density functional calculations yield
insight into the electronic structure and the geometry of the exchange-bond
network of both PdAs2O6 and NiAs2O6, and provide a semi-quantitative
explanation of the large amplitude difference between their primary exchange
interaction parameters
Pressure-temperature phase diagram of SeO2. Characterization of new phases
We have investigated SeO2 at high pressures and high temperatures. Two
new phases (beta-SeO2 and gamma-SeO2) and the boundary separating them
have been found, following experimental runs performed at pressures tip
to 15 GPa and temperatures up to 820degreesC. The two phases
crystallize in the orthorhombic system in space group Pmc2(1) (no. 26)
with a = 5.0722(1) Angstrom, b = 4.4704(1) Angstrom, c = 7.5309(2)
Angstrom, V = 170.760(9) Angstrom(3) and Z = 4 for the beta-phase, and
with a = 5.0710(2) Angstrom, b = 4.4832(2) Angstrom, c = 14.9672(6)
Angstrom, V = 340.27(3) Angstrom(3) and Z = 8 for the gamma-phase. Both
phases are stable at ambient pressure and temperature below
-30degreesC. At ambient temperature the phases return to the starting
phase (alpha-SeO2) in a few days. We discuss our findings in relation
to a previous report of in-situ measurements at high pressures and
ambient temperature. (C) 2004 Elsevier Inc. All rights reserved
Monopoly pricing in the binary herding model
How should a monopolist price when selling to buyers who learn from each other’s decisions? Focusing on the case in which the common value of the good is binary and each buyer receives a binary private signal about that value, we completely answer this question for all values of the production cost, the precision of the buyers’ signals, and the seller’s discount factor. Unexpectedly, we find that there is a region of parameters for which learning stops at intermediate and at extreme beliefs, but not at beliefs that lie between those intermediate and extreme beliefs
The Effect of Better Information on Income Inequality
Information system, Income inequality, Risk sharing markets, D80, J24, J30,