Spin reorientation and structural changes in NdFeO₃

Abstract

The crystal structure and the Fe3+ magnetic moment ordering in NdFeO3 have been studied by high-resolution neutron powder diffraction at temperatures ranging from 1.5 to 300 K. Between 100 and 200 K a spin reorientation transition is observed with gradual changes of the directions of the Fe3+ ordered magnetic moments. The spin reorientation temperature range is associated with changes of the crystal structure. The b lattice parameter has a broad local minimum in the spin reorientation region. There is also a coherent rotation of the FeO6 octahedra with an increase of the Fe–O–Fe angles with increasing temperature. These structural changes tend to increase the strength of the in-plane (a,b) Fe–Fe interactions and to decrease the strength of Fe–Fe interactions along the c-axis as the temperature increases. The Fe3+ magnetic moment ordering above 200 K is close to the antiferromagnetic Gx type. The total Fe3+ ordered magnetic moment at room temperature equals 3.87(5) μB. Below 100 K the Fe3+ magnetic moment ordering is a combination of the antiferromagnetic Gx and Gz type. The ordered Fe3+ magnetic moment components at 1.5 K are Mx = 1.30(15) μB and Mz = 3.97(5) µB. There is a C-type antiferromagnetic ordering of the Nd3+ magnetic moments at 1.5 K with the ordered Nd3+ moment value of 1.10(7) μB.

Spin reorientation inNdFe0.5Mn0.5O3: Neutron scattering andab initiostudy

“…The neutron diffraction patterns were collected systematically at regular intervals between 4 K to 300 K. In this section, the structural analysis of NFMO in comparison to NdFeO 3 and NdMnO 3 is dicussed. In Table I, [20,44]. We observe A weaker orbital ordering associated with dynamical J-T effect at Mn sites may still be present in the system up to x≈ 0.5 [34,45,46].…”

“…This transition might be continuous/abrupt depending upon the of RE element [9]. NdFeO 3 is one of the well studied family members of orthoferrite materials which exhibits antiferromagnetic ordering and temperature dependent SR [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25]. It crystallizes in orthorhombic crystal structure of the space group P bnm and comprises of highly distorted corner shared Mn(Fe)O 6 octahedra.…”

“…It crystallizes in orthorhombic crystal structure of the space group P bnm and comprises of highly distorted corner shared Mn(Fe)O 6 octahedra. NdFeO 3 is a canted Gtype antiferromagnet with a high Néel temperature (T N ) of 690 K [20]. The magnetic structure is represented as G x F z belonging to irreducible representation Γ 4 , in which the spins form a G-type antiferromagnetic order along a direction(G x ), with a small ferromagnetic component along c direction due to canting (F z ).…”

Exchange Bias Effect in NdFeO_3 System of Nanoparticles

“…2). In the case of NdFeO 3 a spin reorientation transition is observed between 100 and 200 K with gradual changes of the directions of the Fe 3+ ordered magnetic moments [9]. In our paper we defined T SR as the temperature at which the process of reorientation is finished and we assign it to the local minimum on µ(T ) curve (Fig.…”

“…The physical and structural properties of NdFeO 3 were widely studied and they attracted large attention due to interesting magnetic properties such as spin-reorientation phase transition [9]. Magnetic properties of NdFeO 3 are mostly determined by Fe-Fe, Fe-Nd, and Nd-Nd exchange interactions.…”