Crystal structure and complex magnetic properties of R11Pd4In9 compounds (R = Y, Gd–Er). (August 2020) - Baran, S.
Abstract: Magnetic properties of the R11 Pd4 In9 compounds (R = Y, Gd–Er) were investigated by means of X-ray diffraction and magnetic measurements. Three of these compounds, namely those with R = Y, Ho and Er, are newly synthesized. The compounds crystallize in the orthorhombic Nd11 Pd4 In9 -type crystal structure (oC48, Cmmm ) in which the rare earth atoms occupy five nonequivalent sublattices. Magnetic properties of the investigated compounds are related mainly to the R 3+ ions, except the case of Y11 Pd4 In9 which is a Pauli paramagnet. For R = Gd-Er, the values of effective magnetic moments in the paramagnetic state are close to the free R 3+ ion values while the moments in the ordered state at T = 2 K and H = 90 kOe are lower than the respective R 3+ moments. The compounds have complex magnetic properties. All paramagnetic Curie temperatures are positive suggesting that the ferromagnetic interactions are predominant. However, the low temperature data indicate an antiferromagnetic order. With increase of temperature the magnetic properties change from antiferro-to ferrimagnetic and finally to paramagnetic ones. The critical temperatures of magnetic ordering do not fulfill the de Gennes scaling, indicating a crystalline electric field contribution to stabilization of the magnetic order at low temperatures. The neutron diffraction measurements, performed for Ho11 Pd4 In9, reveal a coexistence of two magnetic phases at low temperatures: the antiferromagnetic with propagation vector k = [0, 0, ½] and the ferrimagnetic one with k = [0, 0, 0]. The antiferromagnetic order is predominant at low temperatures while the ferrimagnetic one dominates at intermediate temperatures. Highlights: Crystal structure of R11 Pd4 In9 (R = Y, Ho, Er) is reported for the first time. Magnetic properties of R11 Pd4 In9 (R = Y, Gd–Er) are reported for the first time. Ferro-/ferrimagnetic order develops with decreasing temperature in R11 Pd4 In9, R = Gd–Er. Additional magnetic transitions are found below the respective Curie points. Ho11 Pd4 In9 shows a coexistence of antiferro- and ferrimagnetic structures.