ISSN:
1089-7550
Source:
AIP Digital Archive
Topics:
Physics
Notes:
A puzzle is pointed out concerning the low-temperature behavlor of La2CuO4 and YBa2Cu3O6, the insulating "parents'' of the high-Tc superconductors, and indicate a possible solution. The measured ordered magnetic moment is about 0.64 μB per Cu, in agreement with the value calculated on the basis of the Heisenberg Hamiltonian. But this calculation is within a nearly purely ionic or localized picture of the Cu d hole, the reduction from 1.1 μB (g≈2.2) being entirely due to spin fluctuations. Thus the almost perfect agreement leaves no room for the moment reduction due to covalence or 3d-2p hybridization, expected to be large in these oxides. A possible explanation might lie in the fact that an ostensibly symmetry-based argument relating the calculated moment (in the symmetry-unbroken state) to that measured is not valid, as has recently been shown.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.348039
