149 research outputs found
Exotic (anti)ferromagnetism in single crystals of Pr6Ni2Si3
The ternary intermetallic compound Pr6Ni2Si3, is a member of a structure
series of compounds based on a triangular structure where the number of Pr
atoms in the prism cross section can be systematically varied. Pr6Ni2Si3
contains two distinct Pr lattice sites which result in complex interactions
between the magnetic ions. Extensive measurements of specific heat and
magnetization on single crystal samples indicate that Pr6Ni2Si3 orders with
both a ferromagnet and an antiferromagnet component, with ordering temperatures
of 39.6 K and ~ 32 K, respectively. The ferromagnetic component // c-axis is
accompanied by a large hysteresis, and the antiferromagnetic component,_|_
c-axis is accompanied by a spin-flop-type transition. More detailed
measurements, of the vector magnetization, indicate that the ferromagnetic and
the antiferromagnetic order appear independent of each other. These results not
only clarify the behavior of Pr6Ni2Si3 itself, but also of the other members of
the structure series, Pr5Ni2Si3 and Pr15Ni7Si10.Comment: 9 pages, 13 figures, submitted to PR
Chemical Bonding in Solids
This chapter discusses the various classes of hydride compounds, with a special focus on saline and metallic hydrides as well as oxyhydrides. It includes the following topics: thermodynamic stability, crystal chemistry, synthesis, and physical properties. The chapter also highlights recent progress in understanding hydride ion mobility in alkaline earth hydrides. It further deals with hydride compounds and in particular those containing alkali, alkaline earth, and transition and rare earth metals. The saline hydrides, that is, AH and AeH2 (with A=Li, Na, K, Rb, and Cs; Ae=Mg, Ca, Sr, and Ba) are proper ionic materials, in which hydrogen is present as hydride anions, H−. Saline hydrides show many similarities with their halide analogues, especially concerning crystal and electronic structures and, perhaps to a lesser extent, physical attributes such as brittleness, hardness, and optical properties
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