摘要:

We describe a novelXYmicropositioning stage which operates using a single piezoelectric actuator to produce slip‐stick motion. The stage can be moved in steps as small as 20 nm over an area of 9 mm×9 mm, at translation speeds of up to 0.5 mm/s. Cross coupling between axes is negligible, and the threshold voltage for movement is typically 10 V or less. The device is simple in construction and requires no precision components. The stage is small and robust, requires no mechanical connections, and offers the unique advantage in scanning tunneling microscopy and atomic force microscopy applications of being able to provide aZdisplacement of some microns.

ISSN:0034-6748    

DOI:10.1063/1.1143942

出版商:AIP    

年代:1993

数据来源: AIP

摘要:

A new sample holder for the Janis Supervaritemp Dewar has been designed which allows very accurate temperature readings at the sample and avoids sample breakage by reducing thermally induced stress. In addition, the successful operation of this helium dewar using liquid nitrogen has been achieved allowing temperatures above 80 K, stable to within ±0.04 K, to be obtained.

ISSN:0034-6748    

DOI:10.1063/1.1143890

出版商:AIP    

年代:1993

数据来源: AIP

摘要:

We describe the design of a novel low‐profile valve to isolate a molecular beam source from an ultrahigh vacuum system. The valve thickness is simply the thickness of a standard double‐sided Conflat flange, on which the valve gate and actuation mechanism are assembled in a fully recessed configuration. The valve gate can accommodate a skimmer and/or several source collimating apertures. The manual actuator is mounted radial to the Conflat flange.

ISSN:0034-6748    

DOI:10.1063/1.1143891

出版商:AIP    

年代:1993

数据来源: AIP

摘要:

We propose to use silver tips for scanning tunneling microscopy (STM). Silver is the cheapest noble metal that is practically chemically inactive in the air environment. A simple reliable procedure of the tip preparation and resharpening is presented. The procedure is based on two‐step electrochemical processing resulting in final tip curvature of less than 200 nm in radius as seen by an electron microscope. The tips show durability for at least a week of daily operation in an air STM.

ISSN:0034-6748    

DOI:10.1063/1.1143892

出版商:AIP    

年代:1993

数据来源: AIP

摘要:

For inductively coupled plasma‐mass spectrometry analysis of aqueous solutions the plasma and ion optics are optimized (tuned) using elements added to the solution for that purpose, or suitable elements in the dissolved sample. Laser ablation sampling produces transient signals that are difficult to use for tuning. For laser ablation sampling iodine can be used to produce a stable peak at mass 127 for tuning purposes. Iodine is easily introduced into the argon carrier gas stream by room‐temperature evaporation of a 1‐mm‐size grain. The iodine grain should be supported in a glass tube to avoid reaction with plastic or metal. Iodine apparently does not form significant quantities of polyatomic ions such as ArI+in the plasma, and so does not interfere with the analysis of isotopes having masses ≳127.

ISSN:0034-6748    

DOI:10.1063/1.1143893

出版商:AIP    

年代:1993

数据来源: AIP

摘要:

We have designed and tested a pressure cell for oxygen treatment of small samples. Using this cell, oxygen pressure up to 4 kbar can be applied at temperatures up to 600 °C in a simple, cost effective, and reliable way. We have applied this method to O2doping of high‐temperature superconductors.  

ISSN:0034-6748    

DOI:10.1063/1.1144459

出版商:AIP    

年代:1993

数据来源: AIP

摘要:

A simple pump has been constructed which is useful for stirring gas in a sample cell for gas‐phase nonlinear optics experiments. It uses a piston and has been operated at gas pressures from 0 to 200 atm, and at temperatures from room temperature to 200 °C.

ISSN:0034-6748    

DOI:10.1063/1.1143894

出版商:AIP    

年代:1993

数据来源: AIP

摘要:

This note contains a brief description of a portable type of magnetometer which uses an rf SQUID. In the simplified electronic circuit no low‐frequency modulation is used.  

ISSN:0034-6748    

DOI:10.1063/1.1143895

出版商:AIP    

年代:1993

数据来源: AIP

摘要:

A self‐crowbar switch was operated on the pulsed power generator LIMAY‐I and applied to a gas‐puffz‐pinch load. The radial collapse of the plasma is demonstrated to occur with the aid of the self‐crowbar switch after the applied power pulse has turned off. X‐ray emission was observed to coincide with radial collapse of the plasma, and the pinched plasma was visually observed by an x‐ray pinhole photograph. The x‐ray intensity increased with decrease of the puffed gas density.

ISSN:0034-6748    

DOI:10.1063/1.1143896

出版商:AIP    

年代:1993

数据来源: AIP

摘要:

A simple profilometer based upon a commercial strain gauge force transducer is described. It has been used on polymer film coated substrates to determine film thicknesses on the order of 10.0 &mgr;m. Measured film thicknesses agree with gravimetrically determined values to within ±0.3 &mgr;m.  

ISSN:0034-6748    

DOI:10.1063/1.1143897

出版商:AIP    

年代:1993

数据来源: AIP