Abstract
The results of microhardness measurements on flux-grown crystals of (i) single (pure) rare earth aluminates RAlO3 (R = Eu, Gd, Dy, Er) and rare earth orthochromites RCrO3 (R = Y, Gd, Yb), (ii) rare earth aluminates doped with neodymium, erbium, ytterbium and holmium, and (iii) mixed rare earth aluminate crystals of the type (La1−x ) Pr(x)AlO3 (x=0, 0.25, 0.75 and 1.00) are presented. The variations in the microhardness value with load are non-linear in all cases. Kick's law fails to explain the observed variations. Instead, they are best explained by the application of the idea of materials resistance pressure in the modified law proposed by Hays and Kendall. The results indicate that the doping does not increase the hardness value of crystals in all cases. The hardness instead depends on the composition of the parent material as well as the dopant entering into the crystal lattice. Mixed rare earth aluminate crystals are shown to be harder than those of single rare earth aluminates.
Similar content being viewed by others
References
W. Hayden, W. G. Moffatt andJ. Wulff, “The Structure and Properties of Materials”, Vol. III “Mechanical Behaviour” (Wiley Eastern (P), New Delhi/New York, 1968) p. 1.
K. J. Pratap andV. Hari Babu,Bull. Mater. Sci. 2 (1980) 43.
J. R. Pandya andA. J. Shah Jr, Maharaja Sayajirao University, Baroda, India, Vol. XXX (1981) 53.
D. Saber andA. M. Lejus,Mater. Res. Bull. 16 (1981) 1325.
F. Laville andA. M. Lejus,J. Crystal Growth 63 (1983) 426.
J. R. Pandya, L. J. Bhagia andA. J. Shah,Bull. Mater. Sci. 5 (1983) 79.
J. R. Pandya andL. J. Bhagia,Ind. J. Pure Appl. Phys. 22 (1984) 439.
K. S. Raju,Pramana 8 (1977) 266.
K. S. Raju, R. Godehardt, J. Hopee andE. Pippel,Crystal Res. Technol. 19 (1984) 1127.
K. Sangwal andA. R. Patel,J. Phys. D Appl. Phys. 7 (1974) 2031.
A. R. Patel andS. K. Arora,J. Mater. Sci. 12 (1977) 2124.
M. Lakshmipathi Rao andV. Hari Babu,Ind. J. Pure Appl. Phys. 16 (1978) 821.
K. Narasimha Reddy, M. Lakshmipathi Rao andV. Hari Babu,ibid. 17 (1979) 806.
A. R. Patel andS. K. Arora,Kristal Tech. 13 (1978) 1445.
U. V. Subba Rao andV. Hari Babu,Pramana 11 (1978) 149.
Idem, Ind. J. Phys. 54A (1980) 147.
N. S. Pandya, V. P. Bhatt, Ar Was andG. R. Pandya,Ind. J. Pure Appl. Phys. 15 (1977) 750.
V. P. Bhatt andC. F. Desai,Bull. Mater. Sci. 4 (1982) 23.
P. N. Kotru, K. K. Raina, S. K. Kachroo, B. M. Wanklyn,J. Mater. Sci. 19 (1984) 2582.
P. N. Kotru andB. L. Gupta, (1986) unpublished.
P. N. Kotru, Anima Jain, A. K. Razdan andB. M. Wanklyn, (1986) unpublished.
C. Hays andE. G. Kendall,Metallogr. 6 (1973) 275.
Barbara M. Wanklyn,J. Crystal Growth 5 (1969) 323.
G. Garton andB. M. Wanklyn,ibid. 1 (1967) 164.
G. Y. Chin, L. G. Vanuitert, M. L. Green andG. J. Zydrik,Scripta Metall. 6 (1972) 503.
J. R. Hopkins, J. A. Miller andJ. J. Martin,Phys. Lett. Solids A19 (1933) 591.
P. N. Kotru, Ashok K. Razdan, K. K. Raina andB. M. Wanklyn,J. Mater. Sci. 20 (1985) 3365.
J. W. Davison andW. H. Waughan,Rep. Naval. Res. Lab. Prog. 10 April (1958).
H. Buckle,Metallurg. Rev. 4 (1959) 13.
G. P. Upit andS. A. Varchanya,Phys. Status Solidi A19 (1933) 591.
F. Kick, “Das Gesetz der proportionalen widerstnde and Seine Anwendung” (Felix, Leipzig, 1885).
F. Schultz andH. Hanemann,Z. Metallkde 33 (1941) 124.
E. B. Bergsman, “The Micro-hardness Tester” (Vector Pettersons, Stockholm, 1945).
A. R. G. Brown andE. Ineson,J. Iron Steel Inst. 169 (1951) 376.
R. Mitsche andE. M. Onitsch,Mikroskopie 3 (1948) 257.
W. Bischof andB. Wenderoff,Arch. Eisenhutlenw. 15 (1941–42) 497.
D. R. Tate,Trans. ASM 35 (1945) 374.
E. D. Bernhardt,Z. Metallkde 33 (1951) 135.
N. W. Thibault andN. L. Nyguist,Trans. ASM 38 (1947) 271.
R. Schulze,Feinwerktechnik 55 (1951) 190.
E. M. Onitsch,Mikroskopie 2 (1947) 131.
L. P. Tarasov andN. W. Thibault,Trans. ASM 38 (1947) 331.
R. F. Campbell, Q. Henderson andM. R. Donleavy,Ibid. 40 (1948) 954.
W. Rostoker,J. Inst. Metals 77 (1950) 175.
C. L. Saraf, PhD thesis, M. S. University, Baroda, and personal communication (1971).
A. Edner,Z. Phys. 73 (1932) 632.
W. Metag,Phys. Status Solidi 78 (1932) 363.
H. Shoenfeld,J. Appl. Phys. 75 (1932) 442.
R. L. Fleizcher,ibid. 33 (1962) 3504.
A. A. Urusovskaya, G. F. Dobrazhanski, N. L. Sizova, V. G. Govorkov, Yu. N. Martyshev,Sov. Phys. Crystallogr. 13 (1969) 899.
A. H. Cottrell, “Dislocations and plastic flow in crystals” (Oxford University, 1953) p. 58.
J. N. Plendl andP. J. Gieliesie,Phys. Rev. 125 (1962) 828.
J. J. Gilman,J. Appl. Phys. 44 (1973) 982.
G. Y. Chin, V. L. G. Vitert, M. L. Green, G. J. Zydzik andT. V. Kometani,Ser. Met. 6 (1972) 475.
Idem, J. Amer. Ceram Soc. 56 (1973) 7.
A. R. Patel andC. C. Desai,J. Phys. D Appl. Phys. 3 (1970) 1645.
W. G. Johnston,J. Appl. Phys. 33 (1962) 2050.
J. S. Dryden, S. Morimoto andJ. S. Cook,Phil. Mag. 12 (1965) 116.
M. L. Green andG. Zydzik,Scripta Metall. 6 (1972) 10.
R. L. Fleischer,Acta Metall. 10 (1962) 835.
C. W. A. Newey,Trans. Brit. Ceram. Soc. 62 (1963) 739.
C. W. A. Newey, R. P. Harison andP. L. Pratt,Proc. Brit. Ceram. Soc. 6 (1966) 305.
N. Suszynksa,Phys. Status Solidi A6 (1971) 67.
A. F. Armington, H. Dosen andH. Lipson,J. Electron. Mater. 2 (1973) 127.
S. V. Labenets andV. I. Startsev,Sov. Phys. Solid State 10 (1968) 15.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Kotru, P.N., Razdan, A.K. & Wanklyn, B.M. Microhardness of flux grown pure doped and mixed rare earth aluminates and orthochromites. J Mater Sci 24, 793–803 (1989). https://doi.org/10.1007/BF01148759
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF01148759