Ferrimagnetism

About: Ferrimagnetism is a research topic. Over the lifetime, 7609 publications have been published within this topic receiving 151259 citations.

Single Crystal Growth of Manganese Gallium Nitride Using Mn—Ga—Na Melt.

Abstract: Manganese gallium nitride (Mn4−xGaxN) single crystals as well as Mn-doped GaN single crystals were prepared by heating a Mn–Ga–Na melt at 750 °C and 5 MPa of N2 pressure. The Mn4−xGaxN crystals had the cubic anti-perovskite-type structure (space group: Pm 3 m ) with a lattice parameter a=3.8886(9) A. The single crystals exhibited magnetic transitions from a ferrimagnetic phase with a spin–glass-like disorder to an antiferromagnetic phase at 107 K, and then to a paramagnetic phase at 270 K. From these magnetic transition temperatures, the composition of the Mn4−xGaxN single crystals was estimated to be Mn3.07Ga0.93N.

Relaxation of Gallium Nuclei in Ga3+‐Doped YIG

Abstract: We report a study of the NMR of gallium impurities in YIG. In this magnetic system a nonmagnetic impurity is added to a ferrimagnetic host where the observed nucleus is located at the magnetic defect site. This nucleus is coupled to the surrounding magnetic ions by a transferred hyperfine interaction, similar in form to the Heisenberg interaction, giving rise to local impurity states. These local states have been of much theoretical interest in recent years. Spin echo techniques were used to measure the relaxation behavior of 71Ga and 69Ga in single‐domain samples of Y3Fe5−xGaxO12 for x between 0.05 and 1.0. The observed linewidth at x=0.25 shows a strong inhomogeneous broadening due mainly to the interaction between impurity sites. T1 is very sensitive to concentration, ranging from 1 sec for x=0.25 to about 10 msec for x=1.0 and varies as 1/T for T between 1.9° and 4.2°K. In contrast T2−1 varies almost linearly with concentration and is temperature independent.

Introduction to Special Section: Frontiers in Rock Magnetism and Domain Theory—Basic and Applied

Abstract: Kittel [1946], then of the erstwhile Bell Laboratories, predicted that magnetization reversal in small uniformly magnetized, or single-domain particles will occur only if a large negative magnetic field (∼2×102 mT) was applied. In other words, once magnetically saturated and left in the ambient Earth's magnetic field, the single-domain (SD) particles would exhibit high values of magnetic remanence, as well as high coercive forces. The terrestrial geomagnetic “recording media,” sediments and rocks with strongly ferrimagnetic particles in them, owe their magnetic stability or “memory” over geological timescales to such high coercive forces. Stacey (1963) applied Kittel's theory to calculate SD size thresholds for magnetite and hematite, the two most common iron oxide minerals in the Earth's crust.

Anisotropy in Magnetic and Transport Properties of GdCrSb3.

Abstract: We report the first measurements of anisotropy in magnetic susceptibility, magnetization, and electrical resistivity using single crystals of GdTSb3 (T = Cr, V). GdTSb3 is a quasi-two dimensional system with orthorhombic crystal structure (space group: Pbcm). Unlike the other light rare earth chromium antimonides (R = Ce–Nd, Sm), in which two magnetic transitions are observed, GdCrSb3 undergoes a single ferrimagnetic transition at TC=86 K, which is evident in both the magnetic susceptibility and electrical resistivity. Within the b–c plane, GdCrSb3 is found to have metallic behavior from 5 to 300 K, but it is found to have insulating behavior (dρa/dT