Mössbauer-effect, magnetic, and neutron-diffraction study of NaFeP2O7

R.C. MERCADER; L. TERMINIELLO; GARY L. LONG; D.G. REICHEL; K. DICKHAUS; R. D. ZYSLER; R.D. SÁNCHEZ; M. TOVAR

PHYSICAL REVIEW B

AMER PHYSICAL SOC

Lugar: New Y; Año: 1990 vol. 42 p. 25 - 32

1098-0121

Neutron-diffraction, magnetic-susceptibility, specific-heat, and Mössbauer-effect studies of NaFeP2O7 reveal that it is a normal Heisenberg isotropic three-dimensional antiferromagnetic material with a Néel temperature of 29.0 K. NaFeP2O7 has the monoclinic P21/c magnetic space group, which is the same as the nuclear crystallographic space group. The easy axis of magnetization lies in the monoclinic ac plane at an angle of 21.0° from the c axis. The specific-heat measurements reveal a λ-type anomaly at 28.7(2) K. A molecular-field model analysis indicates that the intrasublattice magnetic exchange coupling Jaa=Jbb=-0.37 cm-1, whereas the intersublattice coupling Jab=-0.61 cm-1. No evidence for L-type ferrimagnetism is observed.