Colossal magnetoresistance in EuZn2P2 and its electronic and magnetic structure
307-01 Experimental Condensed Matter Physics
12 July 2023
Type(s) of data
We investigate single crystals of the trigonal antiferromagnet EuZn2P2 (P-3m1) by means of electrical trans-
port, magnetization measurements, x-ray magnetic scattering, optical reflectivity, angle-resolved photoemission
spectroscopy (ARPES), and ab initio band structure calculations (DFT + U ). We find that the electrical resistivity
of EuZn2P2 increases strongly upon cooling and can be suppressed in magnetic fields by several orders of
magnitude (colossal magnetoresistance effect). Resonant magnetic scattering reveals a magnetic ordering vector
of q = (0 0 1/2 ), corresponding to an A-type antiferromagnetic order, below TN = 23.7 K. We find that the
moments are canted out of the a-a plane by an angle of about 40° ± 10° and aligned along the  direction
in the a-a plane. We observe nearly isotropic magnetization behavior for low fields and low temperatures which
is consistent with the magnetic scattering results. The magnetization measurements show a deviation from the
Curie-Weiss behavior below ≈150 K, the temperature below which also the field dependence of the material’s
resistivity starts to increase. An analysis of the infrared reflectivity spectrum at T = 295 K allows us to resolve
the main phonon bands and intraband and interband transitions, and estimate indirect and direct band gaps of
E_opt,i = 0.09 and E_opt,d = 0.33 eV, respectively, which are in good agreement with the theoretically predicted
ones. The experimental band structure obtained by ARPES is nearly T independent above and below T_N . The
comparison of the theoretical and experimental data shows a weak intermixing of the Eu 4f states close to the
point with the bands formed by the phosphorous 3p orbitals leading to an induction of a small magnetic moment
at the P sites.
Raw data of the figures from the original publication.
The data are available both as Origin file or as plain ASCI data.
|Type of identifier||Identifier||Type of publication||Type of relation|