OXYGEN-ISOTOPE EFFECT ON NEEL TEMPERATURE IN VARIOUS ANTIFERROMAGNETIC CUPRATES

被引：55

作者：

ZHAO, GM

SINGH, KK

MORRIS, DE

机构：

[1] Morris Research Inc., Berkeley, CA 94704

来源：

PHYSICAL REVIEW B | 1994年 / 50卷 / 06期

关键词：

D O I：

10.1103/PhysRevB.50.4112

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

Oxygen isotope effect on Neel temperature (T(N)) has been studied in the antiferromapetic cuprates La2CuO4, Gd2CuO4, Gd1.9Ce0.1CuO4, and CuO. For stoichiometric La2CuO4 with T(N) appproximately 310 K, the Neel temperature of the O-18 samples is approximately 1.8 K lower than the O-16 samples. For oxygen-annealed La2CuO4 samples (in 0.10 and 0.15 bar oxygen partial pressures), the Neel temperatures of the O-18 samples are approximately 3.3-4.7 K lower than the O-16 samples. For La2CuO4 annealed in 0.6 bar oxygen, the Neel temperatures of the O-16 and O-18 samples are nearly equal due to segregation into oxygen-rich and oxygen-poor phases. For the other antiferromagnetic cuprates (which lack apical oxygen), we find a negligible oxygen isotope effect on T(N). We suggest that the observed oxygen isotope effect on T(N) of La2CuO4 originates from the oxygen-mass dependences of J (in-plane antiferromagnetic exchange energy) due to the nonadiabatic motion of apical oxygen.

引用

页码：4112 / 4117

页数：6

共 19 条

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