Study of the low‐temperature properties of multiferroic YbMnO₃ and YbMn_0.7Ga_0.3O₃ single crystals

Abstract

The specific heat, magnetization, and magnetocapacitance of YbMnO3 and YbMn0.7Ga0.3O3 multiferroic single crystal manganites were measured in magnetic field. From the specific heat data it was stated that the effect of dilution of Mn by non‐magnetic Ga3+ ions led to reduced Mn magnetic interactions and suppressed the magnetic ordering of Yb in both the 2a and 4b positions. Combining the results of all measurements, the magnetic‐field–temperature phase diagram YbMnO3 was drawn, and the types of the Yb magnetic ordering in both positions were determined.

Thermodynamic properties of multiferroic Mg doped YbMnO3

“…The larger molecular field for x = 0.05 sample results in higher T N as observed. These molecular field and Schottky gap values are nearly the same as reported values in literature[10,11].C mag /T vs. T curves for YbMnO 3 and Yb 0.95 Mg 0.05 MnO 3 are shown in…”

“…The Schottky anomaly for these samples is due to the Zeeman like splitting of crystal fields in ground state multiplet of the Yb 3+ ions [10,11]. Assuming that the effective moment of Yb 3+ ions in the ground state is l Yb and that the splitting of the doublet is D Sch = 2l Yb H mf, contribution from a two level Schottky function should fit the specific heat data at low temperatures (T < 15 K).…”

“…Assuming that the effective moment of Yb 3+ ions in the ground state is l Yb and that the splitting of the doublet is D Sch = 2l Yb H mf, contribution from a two level Schottky function should fit the specific heat data at low temperatures (T < 15 K). We have used the Schottky function [11] for a two level system given by…”

“…They further observed that (1) Ca doping slightly decreased the Néel temperature and (2) a decrease in magnitude of the sharp peak which they attributed to a decrease in number of Yb 3+ ions. Measurements of heat capacity of YbMnO 3 and YbMn 0.7 Ga 0.3 O 3 single crystals by Abramov et al [11] showed that the substitution of Mn by non-magnetic Ga 3+ ions led to reduced Mn magnetic interactions and, therefore, suppressed the magnetic ordering of Yb in both 2a and 4b positions. Recently we have reported the effect of Mg doping on structure and magnetism of multiferroic YbMnO 3 [12].…”

Magnetocaloric effect in hexagonal Yb0.9Mg0.1MnO3

“…is the Schottky contribution n ¼2/3 for Yb 4b sites taken from literature [9]. with N a being Avogadro's number and k Boltzmann's constant.…”