## Abstract

The hole numbers at Cu and oxygen sites in the CuO_{2} plane in a wide variety of high-T_{c} materials have been extracted from the measured nuclear quadrupole frequency, v_{Q}. The hole number in the [formula omitted] orbit, [formula omitted] is found to be more than 0.85 in La_{2-x}Sr_{x}CuO_{4} (x=0.075-0.24), while decreases to 0.74 in Tl_{2}Ba_{2}Ca_{2}Cu_{3}O_{10}. Thus estimated [formula omitted] is supported by the result that the orbital Knight shift along the c-axis, [formula omitted] increases in proportion to [formula omitted] In contrast to the decrease of [formula omitted] the hole number in the O-2p_{σ} orbit, [formula omitted] increases in going from the La- to the Tl-systems. It has been found that T_{c} is determined by two parameters about holes, i.e., [formula omitted] and [formula omitted] The former tells the microscopic “doping level” of the CuO_{2} plane, while a smaller [formula omitted] results in a weaker antifer-romagnetic spin fluctuations of low energy. It has been found that not only a proper [formula omitted] but also a sufficiently small [formula omitted] are needed to obtain a high value of T_{c}.

Original language | English |
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Pages (from-to) | 2524-2532 |

Number of pages | 9 |

Journal | journal of the physical society of japan |

Volume | 64 |

Issue number | 7 |

DOIs | |

Publication status | Published - Jul 1995 |

Externally published | Yes |

## Keywords

- NMR
- T
- high-T oxides
- hole distribution
- hole number
- nuclear quadrupole frequency

## ASJC Scopus subject areas

- Physics and Astronomy(all)