Cantilever deflection associated with hybridization of monomolecular DNA film

Yue Zhao, Baskar Ganapathysubramanian, and Pranav Shrotriya

Hybridization of single stranded DNA immobilized on a microcantilever surface leads to cantilever deflection, which may be used as a method for detection of pathogens and biohazards. This paper presents an investigation of the underlying mechanism behind the deflection and compares numerical predictions with experimental results.

J. Appl. Phys. 111, 074310 (2012)

Tunable magnetocaloric effect near room temperature in La_0.7-xPr_xSr_0.3MnO₃ (0.02 ≤ x ≤ 0.30) manganites

YingDe Zhang, Paula J. Lampen, The-Long Phan, Seong-Cho Yu, Hariharan Srikanth, and Manh-Huong Phan

The authors present a systematic investigation of the magnetic and magnetocaloric properties of La_0.7-xPr_xSr_0.3MnO₃ using temperature dependent magnetization measurements and Arrott analysis.

J. Appl. Phys. 111, 063918 (2012)

Electromigration study of copper lines on steps prepared by a plasma-based etch process

Chi-Chou Lin and Yue Kuo

This paper describes the examination of sub-micron copper interconnect lines over a step from one material to another by measurements of the electromigration phenomenon. The team was able to identify dielectric topography and test temperature of the systems as critical factors for the lifetime of the copper line.

J. Appl. Phys. 111, 064909 (2012)

Measurement of semiconductor surface potential using the scanning electron microscope

Jennifer T. Heath, Chun-Sheng Jiang, and Mowafak M. Al-Jassim

The authors study the voltage contrast effect in the scanning electron microscope (SEM) using samples that have an abrupt heterojunction or a diffused homojunction. The secondary electron (SE) signals were calibrated for the samples by studying them at varying applied biases. As a result, the near-surface potentials and related information were accurately measured with an SEM.

J. Appl. Phys. 111, 046103 (2012)

Memory effects in superparamagnetic and nanocrystalline Fe₅₀Ni₅₀ alloy

D. De, A. Karmakar, M. K. Bhunia, A. Bhaumik, S. Majumdar, and S. Giri

The authors investigate a single structural phase of a nanocrystalline Fe₅₀Ni₅₀ alloy that is embedded in an amorphous silica matrix having volume fractions of 1%, 5%, and 10%. Results indicate that the nanoparticles can exhibit superparamagnetic behavior and the authors discuss this characteristic in relation to observed memory effects.

J. Appl. Phys. 111, 033919 (2012)

Fluctuation modes of nanoconfined DNA

Alena Karpusenko, Joshua H. Carpenter, Chunda Zhou, Shuang Fang Lim, Junhan Pan, and Robert Riehn

The authors investigate the fluctuations of nanoconfined DNA on large length scales and determine that the normal modes of an oscillator chain can accurately describe the fluctuations. However, this description breaks down beyond a length scale at which finite extensibility and volume interactions become dominant.

J. Appl. Phys. 111, 024701 (2012)

Transient electron transport properties of multiple quantum dots systems

E. Taranko, M. Wiertel, and R. Taranko

The authors present a theoretical study of the transient electron transport in the multiple quantum dots (QDs) systems forced by the suddenly applied bias voltage. The authors argue that a careful inspection of the transient current beat patterns can provide information about the inter-dot hopping amplitudes, quantum dots energy levels and their occupancies before the abrupt change of the bias voltage is made.

J. Appl. Phys. 111, 023711 (2012)

Quantum confinement in Si and Ge nanostructures

E. G. Barbagiovanni, D. J. Lockwood, P. J. Simpson, and L. V. Goncharova

The authors apply perturbative effective mass theory as a broadly applicable theoretical model for quantum confinement (QC) in all Si and Ge nanostructures including quantum wells (QWs), wires (Q-wires), and dots (QDs). Crystalline and amorphous quantum systems were considered separately. The authors found that crystalline materials are best described by a medium confinement model, while amorphous materials exhibit strong confinement regardless of the dimensionality of the system.

J. Appl. Phys. 111, 034307 (2012)

Impact ionization in quantum well infrared photodetectors with different number of periods

Shan Dong, Ning Li, Sihai Chen, Xihui Liu, and Wei Lu

The authors present a detailed investigation of the photocurrent accompanied with impact ionization effect in In_0.15Ga_0.85As/GaAs multiple quantum well infrared photodetectors (QWIPs) with 10 and 50 periods. The authors observe a remarkable enhancement at high electric field in the sample with 50 periods and a negative differential conductivity in the sample with 10 periods. A theoretical model of the multiplication factor M varying with impact ionization coefficient α, capture probability pc, and well number N is provided to clarify the observed phenomena.

J. Appl. Phys. 111, 034504 (2012)

A simple method for direct observation of the converse magnetoelectric effect in magnetic/ferroelectric composite thin films

Zheng Li, Jiamian Hu, Li Shu, Yi Zhang, Ya Gao, Yang Shen, Yuanhua Lin, and C. W. Nan

The authors present a novel method to directly observe the pure converse magnetoelectric (ME) effect in two magnetic/ferroelectric (FE) composite thin films. The authros show significant strain-mediated converse ME coupling in both cases.

J. Appl. Phys. 110, 096106 (2011)