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## Full-Text Articles in Physics

Correlation Functions For Ionic Motion From Nmr Relaxation And Electrical Conductivity In The Glassy Fast-Ion Conductor (Li2s)0.56(Sis2)0.44, Ivar Svare, Ferdinando Borsa, D. R. Torgeson, Steve W. Martin

#### Correlation Functions For Ionic Motion From Nmr Relaxation And Electrical Conductivity In The Glassy Fast-Ion Conductor (Li2s)0.56(Sis2)0.44, Ivar Svare, Ferdinando Borsa, D. R. Torgeson, Steve W. Martin

*Materials Science and Engineering Publications*

The Li7 NMR spin-lattice relaxation and the electrical conductivity in the typical glassy fast-ion conductor (Li2S)0.56(SiS2)0.44 are discussed from models of Li+ionic motion with distributions of activation energies, as well as from stretched-exponential time-correlation functions. The measured correlation times from the two effects differ by two orders of magnitude, and the derived distributions are shifted greatly relative to each other. We relate the great differences to percolation around the high barriers in the distribution. We present a phenomenological theory that yields good quantitative fits to the observed NMR relaxation with a Gaussian distribution, and ...

Modeling Of Micromagnetic Barkhausen Activity Using A Stochastic Process Extension To The Theory Of Hysteresis, David C. Jiles, Levent B. Sipahi, G. Williams

#### Modeling Of Micromagnetic Barkhausen Activity Using A Stochastic Process Extension To The Theory Of Hysteresis, David C. Jiles, Levent B. Sipahi, G. Williams

*Materials Science and Engineering Publications*

Recent work by Bertotti [IEEE Trans. Magn. **MAG‐24**, 621 (1988)] and others has shown that it is possible to model the micromagnetic Barkhausen discontinuities at the coercive point using a two‐parameter stochastic model. However, the present formulation of the model is restricted to limited regions of the hysteresis curve over which *dM*/*dH* is approximately constant and when*dH*/*dt* is held at a constant rate. A natural extension of this model is to take the basic result, in which the level of Barkhausen activity in one time period is related to the activity in the previous time ...

Comprehensive Analysis Of Barkhausen Emission Spectra Using Pulse Height Analysis, Frequency Spectrum, And Pulse Wave Form Analysis, Levent B. Sipahi, David C. Jiles, D. Chandler

#### Comprehensive Analysis Of Barkhausen Emission Spectra Using Pulse Height Analysis, Frequency Spectrum, And Pulse Wave Form Analysis, Levent B. Sipahi, David C. Jiles, D. Chandler

*Materials Science and Engineering Publications*

The dependence of magnetic Barkhausen emissions (MBE) upon both field excitation and detection frequencies and excitation wave form was studied in order to investigate two of several crucial factors which affect the emissions. Sinusoidal, triangular, and square wave forms were used to generate the MBE and the pulse height spectra, frequency spectra, and pulse wave forms of these signals were analyzed. The frequency spectra of sinusoidal and triangular alternating field excitations showed similar behavior but the spectrum under square wave excitation was different due to the existence of high frequency components during square wave switching. As yet, no common standard ...