Bonding, Moment Formation, and Magnetic Interactions in Ca14MnBi11 and Ba14MnBi11

The ``14-1-11'' phase compounds based on magnetic Mn ions and typified by Ca14MnBi11 and Ba14MnBi11 show unusual magnetic behavior, but the large number (104) of atoms in the primitive cell has precluded any previous full electronic structure study. Using an efficient, local orbital based method within the local spin density approximation to study the electronic structure, we find a gap between a bonding valence band complex and an antibonding conduction band continuum. The bonding bands lack one electron per formula unit of being filled, making them low carrier density p-type metals. The hole resides in the MnBi4 tetrahedral unit and partially compensates the high spin d^5 Mn moment, leaving a net spin near 4 \mu_B that is consistent with experiment. These manganites are composed of two disjoint but interpenetrating `jungle gym' networks of spin 4/2 MnBi4^{9-} units with ferromagnetic interactions within the same network, and weaker couplings between the networks whose sign and magnitude is sensitive to materials parameters. Ca14MnBi11 is calculated to be ferromagnetic as observed, while for Ba14MnBi11 (which is antiferromagnetic) the ferro- and antiferromagnetic states are calculated to be essentially degenerate. The band structure of the ferromagnetic states is very close to half metallic.Comment: 17 pages, containing 10 postscript figures and 5 tables. Two additional figures (Fig.8 and 11 of the paper) are provided in JPG format in separate files. Submitted to Phys. Rev. B on September 20th 200

Macrosocial determinants of population health in the context of globalization

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/55738/1/florey_globalization_2007.pd

Introducing the Modified Paranormal Belief Scale: Distinguishing Between Classic Paranormal Beliefs, Religious Paranormal Beliefs and Conventional Religiosity Among Undergraduates in Northern Ireland and Wales

Previous empirical studies concerned with the association between paranormal beliefs and conventional religiosity have produced conflicting evidence. Drawing on Rice’s (2003) distinction between classic paranormal beliefs and religious paranormal beliefs, the present study proposed a modified form of the Tobacyk Revised Paranormal Belief Scale to produce separate scores for these two forms of paranormal belief, styled ‘religious paranormal beliefs’ and ‘classic paranormal beliefs’. Data provided by a sample of 143 undergraduate students in Northern Ireland and Wales, who completed the Francis Scale of Attitude toward Christianity alongside the Tobacyk Revised Paranormal Belief Scale, demonstrated that conventional religiosity is positively correlated with religious paranormal beliefs, but independent of classic paranormal beliefs. These findings provide a clear framework within which previous conflicting evidence can be interpreted. It is recommended that future research should distinguish clearly between these two forms of paranormal beliefs and that the Tobacyk Revised Paranormal Beliefs Scale should be routinely modified to detach the four religious paranormal belief items from the total scale score