Hall effect of Sr3Ru2O7

The presence of Ru-O bilayers in the layered perovskite metal Sr3Ru2O7 coul d be intuitively expected to result in a doubling of the electronic structu re of Sr2RuO4, i.e. four electron-like and two hole-like Fermi surface shee ts. To check this, we have studied the weak-field Hall effect of Sr3Ru2O7 b etween 30 mK and 300 K. In contrast to the Hall coefficient ;in Sr2RuO4, wh ich has two temperature dependent sign changes and is negative at low tempe ratures, that of Sr3Ru2O7 is positive over the whole range studied. Possibl e implications for its electronic structure are discussed. (C) 2000 Elsevie r Science B.V. All rights reserved.