ﻻ يوجد ملخص باللغة العربية
We show that pharmacosiderite is a novel cluster antiferromagnet comprising frustrated regular tetrahedra made of spin-5/2 Fe3+ ions that are arranged in the primitive cubic lattice. The connectivity of the tetrahedra and the inter-cluster interaction of 2.9 K, which is significantly large compared with the intra-cluster interaction of 10.6 K, gives a unique playground for frustration physics. An unconventional antiferromagnetic order is observed below TN ~ 6 K, which is accompanied by a weak ferromagnetic moment and a large fluctuation as evidenced by Mossbauer spectroscopy. A q = 0 magnetic order with the total S = 0 for the tetrahedral cluster is proposed based on the irreducible representation analysis, which may explain the origin of the weak ferromagnetism and fluctuation.
Muon spin relaxation experiments have been performed in the pyrochlore iridate Pr_2Ir_2O_7 for temperatures in the range 0.025-250 K. Kubo-Toyabe relaxation functions are observed up to > 200 K, indicating static magnetism over this temperature range
Dimensionality is a critical factor in determining the properties of solids and is an apparent built-in character of the crystal structure. However, it can be an emergent and tunable property in geometrically frustrated spin systems. Here, we study t
Pyrochlore lattices, which are found in two important classes of materials -- the $A_2B_2X_7$ pyrochlore family and the $AB_2X_4$ spinel family -- are the quintessential 3-dimensional frustrated lattice architecture. While historically oxides ($X =$~
Magnetic ($chi$), transport ($rho$) and heat capacity ($C_m$)properties of CeIrSi are investigated to elucidate the effect of geometric frustration in this compound with trillium type structure because, notwithstanding its robust effective moment, $m
Thermodynamic properties of cubic Heisenberg ferromagnets with competing exchange interactions are considered near the frustration point where the coefficient $D$ in the spin-wave spectrum $E_{mathbf{k}}sim D k^{2}$ vanishes. Within the Dyson-Maleev