15 research outputs found
Statistical research and simulation of MEMS gyros measurements
This article provides results of the statistical analysis and numerical evaluation of noise level components in the MEMS gyroscopes measurements. The Simulink-model of measurement errors for the ADIS16250 angular rate sensors was build, and test data and simulation results were analyzed
Relaxation in the 3D ordered CoTAC spin chain by quantum nucleation of 0D domain walls
We have shown that resonant quantum tunnelling of the magnetisation (QTM),
until now observed only in 0D cluster systems (SMMs), occurs in the molecular
Ising spin chain, CoTAC ([(CH_3)_3NH]CoCl_3 - 2H_2O) which orders as a canted
3D-antiferromagnet at T_C=4.15 K. This effect was observed around a resonant
like field value of 1025 Oe. We present here measurements of the relaxation of
the magnetisation as a function of time, from the zero field cooled (ZFC)
antiferromagnet state and from the saturated ferromagnet state. We show that,
at the resonant field, the relaxation from the saturated state occurs in a
complicated process, whereas, surprisingly, in the case of the ZFC state, the
relaxation is exponential.Comment: 4 pages, 5 figures, LT25 proceeding
Crystalline Structure of Potassium Holmium Double Tungstate
The potassium holmium double tungstate was prepared by using top seeded solution growth technique. Structural investigations have been performed at room temperature. The KHo(WO4)2 single crystal belongs to the monoclinic space group C2/c with the unit-cell parameters: a = 10.624(2) Å, b = 10.352(2) Å, c = 7.5434(15) Å, β = 130.7
Resonant quantum tunneling of spin chains in a three-dimensional magnetically ordered state
Resonant quantum tunneling of spin chains in a three-dimensionnal magnetically ordered state
5 pages, 6 figuresInternational audienceWe show that resonant quantum tunneling of the magnetization, until now observed only in zero-dimensional (0D) cluster systems, occurs in the molecular Ising spin chain , which orders as a canted 3D-antiferromagnet at . We present three features that prove unambigously the existence of resonant quantum tunneling below (): Temperature independent relaxation of the magnetization, speeding up of the relaxation at a well defined field () and increase of the magnetization each time this field is crossed during a succession of minor hysteresis loops. A mechanism is proposed to describe the behavior based on a simple model of 0D domain wall nucleation
Magnetic and resonance properties of the two-dimensional S=1 compound Ni5(TeO3)4Cl2 with frustrated geometry
Microwave absorption in the frustrated ferrimagnet Cu2OSeO3
The resonance properties of a new Cu2OSeO3 ferrimagnet have been investigated in a wide range of frequencies (17-142 GHz) at liquid helium temperature. The resonance data were used to plot the frequency-field curve of the ferromagnetic spectrum described in the model of an anisotropic two-sublattice ferrimagnet. The effective magnetic anisotropy corresponding to the gap in the spin wave spectrum was estimated (3 GHz). It was found that the spectrum has a multicomponent structure due to the diversity of the types of magnetization precession. As the amplitude of the high-frequency magnetic field increased, additional absorption was observed in an external magnetic field below the main resonance field. The addition absorption detected corresponds to a nonuniform nonlinear parametric resonance due to the nonuniformity of the magnetic structure in the ferrimagnetic crystal Cu2OSeO3