Magnetic ordering of Ho and its role in the magnetization reversal and coercivity double peaks in the Ho3Fe5O12 garnet

摘要: Abstract Rare-earth based garnet system, Ho3Fe5O12 shows magnetization compensation phenomenon at Tcomp = 138 K and a magnetic transition 50 K. In the present work, we reveal physics of these low temperature transitions by carrying out detailed dc magnetization, ac susceptibility, neutron depolarization, diffraction studies. Interestingly, our study under (≲ 50 Oe) fields has shown previously unknown sign reversal (below Tcomp) that persists down to 5 K, lowest measured temperature. Magnetic measurements moderate between Oe 1 kOe two temperatures (in range 105 – 150 K depending upon applied field value) leading double reversals. for fields ≥ 1 kOe, merge single Tcomp (=138 K). A modified Stoner-Wohlfarth model been used explain asymmetrical nature peak around in dependent coercivity data. The susceptibility supports existence both with an evidence deep minimum (138 K) broad Mesoscopic depolarization revealed zero domain-magnetization state Tcomp. Temperature Ho carries induced moment above due polarizing effect internal magnetically ordered Fe sublattices 567 K, whereas umbrella type ordering sublattice moments appears below Tcomp, resulting distortion unit cell from cubic rhombohedral symmetry. However, 50 K, Ho3+ sites are divided into inequivalent sublattices, having different canting angles, it leads structure. Neutron asymmetric variation tetrahedral, octahedral, dodecahedral at ~ 138 K which is very well supported mean theory calculations. study, have resolved ambiguity rare-earth (Ho3+) its role multiple transitions. utility such compensated ferrimagnetic materials spin polarizers/analyzers fast switching memory devices emphasized.