Peter Goodhew | University of Liverpool (original) (raw)

Papers by Peter Goodhew

Microscopy Today

I bought my last useful pocket calculator in 1975 and I still use it regularly. Every time I pick... more I bought my last useful pocket calculator in 1975 and I still use it regularly. Every time I pick it up I know how to use it, since all the functions I need are printed on its buttons, and I expect to be using it when I retire, if I can still get the batteries. My son bought a “more sophisticated” calculator for his A-levels in 1988 and I inherited it shortly thereafter, it lies in my desk drawer but I cannot use it because it offers so much more than I need and there is too much printed on and around each button. I would need to read the manual every time I wanted to use it. On the desktop close by sits my telephone: It has 46 buttons and a 17-page manual and offers an enticing array of facilities. Unfortunately I only need each of these “facilities” about once a month and have never been able to memorize the necessary procedures. As a result all I can do is answer it when it rings and dial out.

Active learning is a well-established concept in education, although the term itself, since its i... more Active learning is a well-established concept in education, although the term itself, since its initial use in the 1950s (1), has had more currency in the context of schools than universities. The idea might be thought to be embedded in higher education, with a journal entitled Active ...

Scheuer's Liver Biopsy Interpretation, 2010

Brydson/Aberration-Corrected Analytical Transmission Electron Microscopy, 2011

Radiation Effects, 1983

ABSTRACT A systematic TEM investigation has been made of helium bubble growth in type 316 stainle... more ABSTRACT A systematic TEM investigation has been made of helium bubble growth in type 316 stainless steel. Commercial stainless steel samples have been vacuum annealed following room temperature helium implantation to a concentration of 5 × 1026 He m. The bubble growth kinetics have been determined by measuring the mean bubble radius at annealing times in the range 1 to 200 h for temperatures of 873, 923 and 1023 K. At the lower two temperatures the bubble growth mechanism is believed to be migration and coalescence, with the migration limited by volume diffusion of the metal atoms. Four additional anneals for 2 h at temperatures in the range 923-973 K have been made to determine the activation energy for diffusion. This is found to be 4.9 eV (assuming the migration is limited by volume diffusion). At 1023 K and for annealing times of less than 8 h, bubble growth appears to occur mainly by the acquisition of thermal vacancies from the sample surface. At longer annealing times the bubble migration becomes limited by the nucleation of atomic ledges on the bubble facet and the rate of bubble growth is reduced. The ledge energy is estimated to be 1 × 10-11 J-m.

Journal of Physics E: Scientific Instruments, 1971

... Fynn GW and Powell W J A 1971 RRE TN 749 (unlimited ... Early observations were made on fibre... more ... Fynn GW and Powell W J A 1971 RRE TN 749 (unlimited ... Early observations were made on fibres mounted in resin and sectioned with an ultramicrotome (Clinton and Kaye 1965, Johnson and Watt 1967) or on the cut ends of fibres which happened to show fibrils thin enough for ...

Micron (1969), 1980

ABSTRACT The major subject of the review is the determination of the chemical composition of a th... more ABSTRACT The major subject of the review is the determination of the chemical composition of a thin specimen by analysis of the X-rays generated within it in the transmission electron microscope. Most emphasis is placed on the use of energy dispersive X-ray detectors attached to modern CTEM/STEM instruments. The production of characteristic and Bremsstrahlung radiation is described quantitatively and the factors which limit the spatial resolution and accuracy of the analysis are discussed. Analytical procedures are described for both materials and biological specimens and attention is drawn to the many possible sources of spurious data. The differences in specimen preparation techniques which are necessary for analytical microscopy are comprehensively reviewed, as are the methods of measuring specimen thickness.The two major techniques for the quantitative analysis of thin specimens are derived from the basic X-ray generation equations. The application of the Cliff-Lorimer ratio technique to metal and compound specimens and the application of the Hall mass-thickness normalization technique to biological sections are then detailed in the context of the minicomputer routines which are most frequently used for these types of analysis. Finally, the use of analytical microscopy in our laboratory is illustrated with reference to work on the chemistry and microstructure of cement and the identification of crystalline inclusions and inorganic wall components in a marine micro-organism.

MRS Proceedings, 1999

The relaxation of strained layers frequently occurs by the glide of threading dislocations. From ... more The relaxation of strained layers frequently occurs by the glide of threading dislocations. From very early on in the relaxation process, gliding dislocations will be forced to intersect a number of prior dislocations with almost-perpendicular line directions and their progress may be blocked. This effect has been widely reported in semiconductor films, and there is some experimental evidence that it is reduced when layers are grown on vicinal substrates. This implies that the blocking is sensitively dependent on the dislocation configuration and in particular on the dislocation line directions.In this paper the interactions between gliding threading dislocations and the perpendicular or nearly-perpendicular dislocation in their path are modelled quantitatively. The differences arising from different initial dislocation configurations and different predominant line directions are found to be small. Strain relaxation, at least in its early stages, should be virtually independent of t...

Microscopy Today

I bought my last useful pocket calculator in 1975 and I still use it regularly. Every time I pick... more I bought my last useful pocket calculator in 1975 and I still use it regularly. Every time I pick it up I know how to use it, since all the functions I need are printed on its buttons, and I expect to be using it when I retire, if I can still get the batteries. My son bought a “more sophisticated” calculator for his A-levels in 1988 and I inherited it shortly thereafter, it lies in my desk drawer but I cannot use it because it offers so much more than I need and there is too much printed on and around each button. I would need to read the manual every time I wanted to use it. On the desktop close by sits my telephone: It has 46 buttons and a 17-page manual and offers an enticing array of facilities. Unfortunately I only need each of these “facilities” about once a month and have never been able to memorize the necessary procedures. As a result all I can do is answer it when it rings and dial out.

Active learning is a well-established concept in education, although the term itself, since its i... more Active learning is a well-established concept in education, although the term itself, since its initial use in the 1950s (1), has had more currency in the context of schools than universities. The idea might be thought to be embedded in higher education, with a journal entitled Active ...

Scheuer's Liver Biopsy Interpretation, 2010

Brydson/Aberration-Corrected Analytical Transmission Electron Microscopy, 2011

Radiation Effects, 1983

ABSTRACT A systematic TEM investigation has been made of helium bubble growth in type 316 stainle... more ABSTRACT A systematic TEM investigation has been made of helium bubble growth in type 316 stainless steel. Commercial stainless steel samples have been vacuum annealed following room temperature helium implantation to a concentration of 5 × 1026 He m. The bubble growth kinetics have been determined by measuring the mean bubble radius at annealing times in the range 1 to 200 h for temperatures of 873, 923 and 1023 K. At the lower two temperatures the bubble growth mechanism is believed to be migration and coalescence, with the migration limited by volume diffusion of the metal atoms. Four additional anneals for 2 h at temperatures in the range 923-973 K have been made to determine the activation energy for diffusion. This is found to be 4.9 eV (assuming the migration is limited by volume diffusion). At 1023 K and for annealing times of less than 8 h, bubble growth appears to occur mainly by the acquisition of thermal vacancies from the sample surface. At longer annealing times the bubble migration becomes limited by the nucleation of atomic ledges on the bubble facet and the rate of bubble growth is reduced. The ledge energy is estimated to be 1 × 10-11 J-m.

Journal of Physics E: Scientific Instruments, 1971

... Fynn GW and Powell W J A 1971 RRE TN 749 (unlimited ... Early observations were made on fibre... more ... Fynn GW and Powell W J A 1971 RRE TN 749 (unlimited ... Early observations were made on fibres mounted in resin and sectioned with an ultramicrotome (Clinton and Kaye 1965, Johnson and Watt 1967) or on the cut ends of fibres which happened to show fibrils thin enough for ...

Micron (1969), 1980

ABSTRACT The major subject of the review is the determination of the chemical composition of a th... more ABSTRACT The major subject of the review is the determination of the chemical composition of a thin specimen by analysis of the X-rays generated within it in the transmission electron microscope. Most emphasis is placed on the use of energy dispersive X-ray detectors attached to modern CTEM/STEM instruments. The production of characteristic and Bremsstrahlung radiation is described quantitatively and the factors which limit the spatial resolution and accuracy of the analysis are discussed. Analytical procedures are described for both materials and biological specimens and attention is drawn to the many possible sources of spurious data. The differences in specimen preparation techniques which are necessary for analytical microscopy are comprehensively reviewed, as are the methods of measuring specimen thickness.The two major techniques for the quantitative analysis of thin specimens are derived from the basic X-ray generation equations. The application of the Cliff-Lorimer ratio technique to metal and compound specimens and the application of the Hall mass-thickness normalization technique to biological sections are then detailed in the context of the minicomputer routines which are most frequently used for these types of analysis. Finally, the use of analytical microscopy in our laboratory is illustrated with reference to work on the chemistry and microstructure of cement and the identification of crystalline inclusions and inorganic wall components in a marine micro-organism.

MRS Proceedings, 1999

The relaxation of strained layers frequently occurs by the glide of threading dislocations. From ... more The relaxation of strained layers frequently occurs by the glide of threading dislocations. From very early on in the relaxation process, gliding dislocations will be forced to intersect a number of prior dislocations with almost-perpendicular line directions and their progress may be blocked. This effect has been widely reported in semiconductor films, and there is some experimental evidence that it is reduced when layers are grown on vicinal substrates. This implies that the blocking is sensitively dependent on the dislocation configuration and in particular on the dislocation line directions.In this paper the interactions between gliding threading dislocations and the perpendicular or nearly-perpendicular dislocation in their path are modelled quantitatively. The differences arising from different initial dislocation configurations and different predominant line directions are found to be small. Strain relaxation, at least in its early stages, should be virtually independent of t...