Ultrasonic gallium arsenide transducers

Ultrasonic gallium arsenide transducers

T S E N D I N , L. D. Propagation of ultrasound in gas mixteres. Soviet Physics--Acoustics, Vol 13, N o 4 (April-June 1968) pp 521-524 This theoretica...

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T S E N D I N , L. D. Propagation of ultrasound in gas mixteres. Soviet Physics--Acoustics, Vol 13, N o 4 (April-June 1968) pp 521-524 This theoretical paper investigates the p r o p a g a t i o n of s o u n d in a m i x t u r e of two g a s e s w h o s e m o l e c u l e s d i f f e r g r e a t l y in m a s s . It i s a s s u m e d t h a t t h a t the m o l e c u l e s a r e not a p p r e c i a b l y d i f f e r e n t in s i z e a n d that their molar concentrations are similar. A t v e r y low f r e q u e n c i e s , a b s o r p t i o n of the p r o p a g a t e d s o u n d is a t t r i b u t a b l e to the i n t e r a c t i o n b e t w e e n c o m p o n e n t s of the g a s . At i n t e r m e d i a t e f r e q u e n c i e s , the v e l o c i t y of sound shows dispersion and varies inversely w i t h f r e q u e n c y . At v e r y h i g h f r e q u e n c i e s , the v e l o c i t y of s o u n d d e p e n d s on t h e h e a v y p a r t i c l e s a l o n e . (6 R e f e r e n c e s ) ( U l t r a s o n i c s 1969, a b s t r a c t 936) VASIL'EV, V. S., K A N E V S K I I , I. N. Ultrasonic gallium arsenide transducers. Akusticheskii ZhurnaI, Vol 14, N o 3 (1968) pp 4 6 5 - 4 6 7 A b r i e f r e p o r t of p r e l i m i n a r y s t u d i e s of the c h a r a c t e r i s t i c s of t r a n s d u c e r s f o r l o n g i t u dinal ultrasonic waves made from gallium arsenide with p : 1.9~cm, n = 1.9 x 1 0 1 S c m -3, a n d ~ = 1 7 0 0 c m 2 / V . s e c . T h e fabrication procedures are described and the f r e q u e n c y c h a r a c t e r i s t i c s r e p r o d u c e d . ( U l t r a s o n i c s 1969, a b s t r a c t 937) VIKTOROV, I. A. Interaction of R a y t e i g h w a v e s w i t h e l e c t r o n s in a CdS c r y s t a l in the p r e s e n c e of illumination a n d a t r a n s v e r s e e l e c t r i c f i e l d . A k u s t i c h e s k i i Z h u r n a l , Vol 14, No 2 (1968) pp 2 0 4 - 2 0 9 An e x p e r i m e n t a l s t u d y is r e p o r t e d of the i n t e r a c t i o n of u l t r a s o n i c R a y l e i g h w a v e s (30MHz) with c o n d u c t i o n e l e c t r o n s in a CdS c r y s t a l i l l u m i n a t e d by a m e r c u r y l a m p a n d p l a c e d in a c o n s t a n t e l e c t r i c field. By i n v e s t i g a t i n g the a m p l i t u d e of the R a y l e i g h w a v e s in the CdS c r y s t a l a s a f u n c t i o n of t i m e f o l l o w i n g the i n t r o d u c t i o n a n d / o r r e m o v a l of the s o u r c e of e x c i t a t i o n , i n f o r m a t i o n i s o b t a i n e d a b o u t s u r f a c e t r a p s in the l a y e r in w h i c h the w a v e is l o c a l i s e d ()~R 0. 0 5 7 m m a t 30MHz). T h e t h i c k n e s s c a n be r e d u c e d by a f a c t o r of at l e a s t 3 b y p l a c i n g the s p e c i m e n in a n e l e c t r i c f i e l d . ( U l t r a s o n i c s 1969, a b s t r a c t 938) V L A D I M I R T S E V , Yu. V., G O L E N I S H C H E V K U T U Z O V , V. A. Absorption of sound in A I 2 0 3 a n d s i l i c a t e g l a s s e s . A k u s t i e h e s k i i Z h u r n a l , Vol 14, No 1 (1968) pp 1 2 6 - 1 2 7 It is p o i n t e d out t h a t m o s t of the p u b l i s h e d w o r k on a c o u s t i c p a r a m a g n e t i e a b s o r p t i o n h a s b e e n c a r r i e d out in the m i c r o w a v e r a n g e (101°Hz) at h e l i u m t e m p e r a t u r e s , u s i n g s p e c i m e n s with r e l a t i v e l y low i n i t i a l a t t e n u a tion of s o u n d (MgO a n d A1203 with p a r a m a g n e t i c i m p u r i t i e s ) . H o w e v e r , the r a n g e of the s u b s t a n c e s i n v e s t i g a t e d c a n be e x t e n d e d by r e d u c i n g the f r e q u e n c y down to 107-109Hz. The measurements reported here w e r e p e r f o r m e d in the r a n g e 5 x 1 0 6 2 x 10SHz at 300, 77 a n d 4 . 2 ° K a n d i n d i c a t e t h a t t h i s is in f a c t s o . ( U l t r a s o n i c s 1969, a b s t r a c t 939)

VON HESS, H. D., HINSCH, H. U l t r a s o n i c a b s o r p t i o n in g a s e o u s m e t h a n e . A e u s t i e a , Vol 19, No 6 (1967/68) pp 3 4 4 349 The u l t r a s o n i c a b s o r p t i o n of m e t h a n e w a s m e a s u r e d in the r a n g e b e t w e e n 50kHz a n d 600kHz, at t e m p e r a t u r e s b e t w e e n --30 ° a n d + 120°C. M a x i m u m m o l e c u l a r a b s o r p t i o n c a u s e d by v i b r a t i o n a l r e l a x a t i o n w a s o b s e r v e d in t h i s f r e q u e n c y / p r e s s u r e r a n g e . The m e a s u r e m e n t s w e r e p e r f o r m e d with two e q u a l e l e c t r o s t a t i c t r a n s d u c e r s (Sell-type) as transmitter and receiver. Relaxation times and impact rates are calculated from the e x p e r i m e n t a l a b s o r p t i o n p l o t s a n d a r e c o m p a r e d with r e s u l t s o b t a i n e d by o t h e r w o r k e r s . T h e p e a k v a l u e of the a b s o r p t i o n c o e f f i c i e n t is h i g h e r t h a n e x p e c t e d f r o m c o n v e n t i o n a l c a l c u l a t i o n s of the v i b r a t i o n a l s p e c i f i c h e a t . ( U l t r a s o n i c s 1969, a b s t r a c t 940). W E I L , R., G R O V E S , W . O. The elastic constants of gallium p h o s phide. J o u r n a l of A p p l i e d P h y s i c s , Vol 39, No 9 ( A u g u s t 1968) p p 4 0 4 9 - 4 0 5 1 T h e p a p e r g i v e s a c o m p r e h e n s i v e a c c o u n t of the e x p e r i m e n t a l d e t a i l s a n d r e s u l t s . The e l a s t i c c o n s t a n t s w e r e d e t e r m i n e d by m e a s u r e m e n t s of the v e l o c i t y of s o u n d in the samples along various crystallographic directions and polarisations. The velocities w e r e m e a s u r e d by the p h a s e c o m p a r i s o n method. The compressibility, Debye temperature and average longitudinal sound v e l o c i t i e s in G a P a r e c a l c u l a t e d . T h e e l a s t i c c o n s t a n t s of G a P a r e f o u n d to a g r e e with the r e g u l a r i t i e s e s t a b l i s h e d f r o m the m e a s u r e m e n t s of t h e s e c o n s t a n t s in o t h e r III-V c o m p o u n d s . ( U l t r a s o n i c s 1969, a b s t r a c t 941) W O O L L E T T , R. S. P o w e r limitation of sonic transducers. Institute of Electrical and Electronics Engineers Transactions on Sonics and Ultrasonics, Vol SU-15, N o 4, (October 1968) pp 218-228 This paper covers transducers in the audio frequency and ultrasonic ranges, for example those used in industrial ultrasonics and sonar, but excludes transducers for generating intense sound waves in air and praetersonic transducers. The paper surveys sound generating methods and then concentrates on analysis of piezoelectric and piezomagnetic transducer (Ultrasonics 1969, abstract

942) ZEMON, S., et al ]Parametric amplification of u l t r a s o n i c w a v e s in CdS. A p p l i e d P h y s i c s L e t t e r s , Vol 12, No 11 (1 J u n e 1968) pp 3 7 8 - 3 8 0 P a r a m e t r i c a m p l i f i c a t i o n of 0 . 5 G H z u l t r a s o n i c s h e a r w a v e s is o b s e r v e d in p h o t o c o n d u c t i n g (fix 1 0 3 G c m in the d a r k ) CdS a t r o o m temperature for electron drift velocities 0 . 1 4 - 3 . 0 t i m e s the v e l o c i t y of s o u n d . T h e nonlinearity arises from acoustoelectric c o u p l i n g of m o d e s . The g a i n w a s a b o u t 1 O d B / m m - - c o m p a r a b l e to t h a t of a c o n v e n tional acoustic amplifier. The acoustic waves w a v e s w e r e d e t e c t e d by B r i l l o u i n s c a t t e r i n g . (10 R e f e r e n c e s , 2 F i g u r e s ) ( U l t r a s o n i c s 1969, a b s t r a c t 943)

Z I L ' B E R M A N , P. E. Electron drag by ultrasonic waves in conductors. Fizika Tverdogo Tela, Vot I0, N o 7 (1968) pp 2088-2093 A method is put forward for solving the transport equation for electrons interacting with ultrasonic phonons. The distribution function found from this solution has singularities of the delta-function type. A n expression is derived for the acoustoelectric current in the presence of beth a constant electric field and a sound field. The calcula = tions are valid for ql >> 1 were q is the wave n u m b e r and I the electron m e a n free path. (Ultrasonics 1969, abstract 944) Diagnosing with ultrasonics. Design E l e c t r o n i c s , Vol 5, No 9 (June 1968) pp 20, 21 The u s e s of the p u l s e - e c h o t e c h n i q u e a n d the D o p p l e r t e c h n i q u e in d i a g n o s i s a r e o u t l i n e d . E x a m p l e s a r e g i v e n of the t r a c e s s h o w n on the o s c i l l o s c o p e w h e n u l t r a s o n i c s is u s e d (1) to d e t e c t b r a i n m i d l e i n e d i s p l a c e m e n t in n e u r o l o g y , (2) to d e t e c t p e r i c a r d i a l e f f u s i o n in c a r d i o l o g y , (3) to m e a s u r e the b i p a r i e t a l d i a m e t e r of the f o e t a l h e a d in o b s t e t r i c s , (4) to l o c a t e r a d i o l u c e n t f o r e i g n b o d i e s in o p t h a l m o l o g y , (5) to l o c a l i s e e l u s i v e c a l c u l i in kidney s u r g e r y , (6) to l o c a l i z e f o r e i g n b o d i e s in g e n e r a l s u r g e r y . The D o p p l e r m e t h o d of d e t e c t i n g b l o o d f l o w in the f o e t a l h e a r t i s g i v e n . F u t u r e a p p l i c a t i o n s of u l t r a s o n i c s in m e d i c i n e a r e s k e t c h e d a n d c o m m e r c i a l e q u i p m e n t i s d e s c r i b e d . (4 F i g u r e s ) ( U l t r a s o n i c s 1969, a b s t r a c t 945) Soviet a c o u s t i c s d u r i n g t h e l a s t fifty y e a r s . Soviet P h y s i c s - - A c o u s t i c s , Vol 13, No 4 ( A p r i l - J u n e 1968) p p 4 1 5 - 4 5 4 T h i s e d i t o r i a l i s not only a g e n e r a l r e v i e w of the w h o l e f i e l d of Soviet a c o u s t i c s , s i n c e it g i v e s s o m e n o t i o n of the i m p o r t a n c e of u l t r a s o n i c s in the USSR. T h e r e v i e w b e g i n s w i t h the m e a s u r e m e n t , g e n e r a t i o n a n d p r o p a g a t i o n of u l t r a s o n i c s w a v e s by V . A . A l t ' b e r g , P . N. L e b e d e v a n d N. P. K a s t e r i n ( 1 9 0 3 - 1 9 0 6 ) a n d p r o g r e s s e s to s t a t e - o f - t h e - a r t s u m m a r i e s on the f o l l o w i n g t o p i c s : e l e c t r o acoustics, architectural-structural acoustics, a c o u s t i c s of s t u d i o s a n d e l e c t r o a c o u s t i c a l l y equipped auditoriums, noise and vibration c o n t r o l , p h y s i c a l a c o u s t i c s , e f f e c t s of s o u n d on m a t t e r , u l t r a s o n i c e n g i n e e r i n g a n d a c o u s t i c a l t e c h n o l o g y , s o u n d p r o p a g a t i o n in i n h o mogeneous and moving media, acoustical aerohydrodynamics, nonlinear acoustics, speech and hearing, bioacoustics, musical acoustics, acoustical measurements and m e t r o l o g y . ( U l t r a s o n i c s 1969, a b s t r a c t 946) Ultrasonic tests expose hidden fatigue, s t r e s s . Steel, Vol 163, No 1 (July 1968) pp 46, 47 A n o n - d e s t r u c t i v e t e s t i n g t e c h n i q u e is o u t l i n e d f o r a n a l y s i s of f a t i g u e c r a c k i n g a n d residual stress. The ultrasonic equipment employs Rayleigh waves, launched along s t e e l b a r s by L u c i t e w e d g e s , to c h e c k the surface and immediate sub-surface condit i o n s . T h e e q u i p m e n t s h o u l d be on the c o m m e r c i a l m a r k e t in J a n u a r y 1969. (2 F i g u r e s ) ( U l t r a s o n i c s 1969, a b s t r a c t 947)

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