Influence of Ru on Magnetism of $R_{2}{\hbox{Fe}}_{17}$ ($R={\hbox{Y}}$, Lu, and Er)

The study of unusual influence of Ru substitution for Fe on magnetic properties of Lu
₂
Fe
₁₇
is extended to a series of
R
₂
Fe
₁₇
. The work is performed on single-crystalline samples of Lu
₂
Fe
₁₆
Ru, Y
₂
Fe
_17-x
Ru
_x
(0 ≤
x
≤ 1) and Er
₂
Fe
_17-x
Ru
_x
(
x
=0, 1) compounds. The collinear ferromagnetic ground state present in the
R
₂
Fe
₁₇
(Y and Lu) parent alloys is destroyed in
R
₂
Fe
_17-x
Ru
_x
, and antiferromagnetism is stabilized in the whole temperature range of magnetic order. The ordering temperatures of
R
₂
Fe
₁₆
Ru (
R
=Y , Lu, Er) are 120 K, and no evidence of spontaneous magnetization is found in any of the alloys. The Fe sublattice in Er
₂
Fe
₁₆
Ru is most likely to be antiferromagnetic as well, however the type of magnetic order of the Er sublattice is not clear. All the compounds under study possess an easy-plane type of magnetic anisotropy and exhibit wide field-induced hysteretic transitions at low temperatures.